The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

Preconception sleep, pregnancy loss, and adverse pregnancy outcomes among women with a history of pregnancy loss

STUDY QUESTION

Are preconception sleep characteristics associated with pregnancy loss and adverse pregnancy outcomes?

SUMMARY ANSWER

Preconception sleep characteristics were not associated with pregnancy loss, but earlier sleep midpoints were associated with lower risk of adverse pregnancy outcomes, while social jetlag >1 h was associated with greater risk of a composite of adverse pregnancy outcomes.

WHAT IS KNOWN ALREADY

Short sleep duration in mid-pregnancy has been associated with risk of second-trimester pregnancy loss, preterm birth (PTB), and hypertensive disorders of pregnancy (HDP). The relationships between preconception sleep and pregnancy loss, and adverse pregnancy outcomes have not been well characterized, despite plausible links.

STUDY DESIGN, SIZE, DURATION

This was a secondary analysis of a randomized controlled trial conducted between 2006 and 2012 that prospectively followed 1228 women who were attempting to become pregnant after a history of pregnancy loss. Women were followed for ≤6 cycles while attempting pregnancy, and throughout pregnancy if they conceived. Over the follow-up, 140 women withdrew from the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study evaluated baseline, self-reported preconception sleep duration, sleep latency, sleep midpoint, and social jetlag with risk of pregnancy loss and adverse pregnancy outcomes (e.g. PTB, HDP, and gestational diabetes (GDM)) among 1228 women with a history of pregnancy loss in the EAGeR trial. Pregnancy was documented by hCG tests; 797 women became pregnant over the follow-up. Pregnancy losses were defined as any loss after a positive hCG test; there were 188 pregnancy losses. PTB, HDP, and GDM cases were ascertained via medical record abstraction. PTB (n = 53), HDP (n = 62), and GDM (n = 22) were examined as a composite outcome (n = 118) and PTB and HDP were examined individually in exploratory analyses. GDM was not examined individually due to insufficient numbers. Log-Poisson models were used to estimate relative risks (RR) and 95% CIs for associations between preconception sleep characteristics, and pregnancy loss or adverse pregnancy outcomes with adjustment for age, BMI, lifestyle, and sociodemographic factors. Stabilized inverse probability weights were applied to address potential selection bias from loss to follow-up and from restricting to pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

Preconception sleep characteristics were not associated with risk of pregnancy loss. Preconception sleep duration and sleep latency were not associated with risk of the composite adverse pregnancy outcome. Early preconception sleep midpoints were associated with a lower risk of the composite adverse pregnancy outcome (first vs second tertile RR; 0.63, 95% CI: 0.40, 0.98) and preconception social jetlag was associated with a higher risk of the composite adverse pregnancy outcome (>1 vs ≤1 h RR; 1.65, 95% CI: 1.11, 2.44).

LIMITATIONS, REASONS FOR CAUTION

Preconception sleep was restricted to baseline self-report, which may be non-differentially misclassified and may underestimate these associations. The EAGeR study did not measure sleep during pregnancy. There were few adverse pregnancy outcomes and thus limited power to evaluate individual outcomes; the findings could be due to chance.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that preconception sleep is not associated with pregnancy loss, but preconception sleep timing may be relevant for risk of adverse pregnancy outcomes. Additional studies on preconception sleep and adverse pregnancy outcomes are needed given the potential impact of poor sleep on pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

Joshua R. Freeman and this work were supported by the Intramural Research Program Cancer Research Training Award, National Cancer Institute, National Institutes of Health (ZIA CP010197), and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (Contract numbers: HHSN267200603423, HHSN267200603424, HHSN267200603426, HHSN275201300023I). Dr Silver received NIH funding through the listed contracts as site-PI for the original EAGeR trial at the University of Utah. Dr O'Brien reports receiving funding from the Star Legacy Foundation (paid to institution); an advisory board role at the Star Legacy Foundation; and receiving travel support from the Star Legacy Foundation. Dr Dunietz reports a role as Associate Editor at Human Reproduction and a role on the Journal Editorial Board of SLEEP. Dr Purdue-Smithe is an employee of Merck & Co. and has received stock compensation as an employee of Merck & Co. in the past 36 months. The work in this manuscript was completed before Dr Purdue-Smithe's employment at Merck & Co. and is unrelated to Dr Purdue-Smithe's work at the company. Dr Silver reports royalties or licenses from BJOG and UpToDate, Inc. in the past 36 months, receiving payment or honoraria for Grand Rounds in the past 36 months, and participating on a Data Safety Monitoring Board or Advisory Board for a National Institutes of Health-funded Apple Trial in the past 36 months. The other authors report there are no competing interests to declare.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT00467363.

Role of fibrinogen-like 2 (FGL2) proteins in implantation: Potential implications and mechanism

Fibrinogen-like (Fgl2) protein belongs to fibrinogen super family, which catalyzes the conversion of prothrombin to thrombin and is involved in the coagulation process. There are two different forms of functional Fgl2 protein: membrane associated Fgl2 (mFgl2) and soluble Fgl2 (sFgl2). mFgl2, as a type II transmembrane protein with property with prothrombinase activity from its N-terminal fragment, was extensively secreted or expressed by inflammatory macrophages, dendritic cells (DCs), Th1 cells and endothelial cells. While sFgl2 was mainly produced by regulatory T cells (Tregs) and then secreted into the vasculature, which contributes to autoimmune disease by regulating maturation of (DCs), polarization of macrophage, inhibiting T cell proliferation and differentiation and inducing apoptosis of B cells. In particular, emerging evidence has shown that Fgl2 is implicated in female reproductive system that contributes to embryo development, ovarian granulosa cells differentiation and implantation failure. This article summarizes the role and potential mechanisms of Fgl2 in reproduction and identifies research gaps along with the future directions.

Effect of 1-nitropyrene exposure on the biological behavior of trophoblast cells

1-nitropyrene (1-NP) is a toxic component of PM2.5 that adversely affects human health, especially pregnant women; however, the mechanisms are still unclear. This study aims to explore the mechanisms by which 1-NP influences trophoblast cell behaviors. HTR8/Svneo cells were treated by different concentrations of 1-NP (0, 5, 10, 20 μM) to assess clonogenic, invasive, and migratory abilities. Western blot analysis was used to assess the expression of EMT and Wnt/β-catenin pathway proteins. 1-NP significantly inhibited HTR8/Svneo cell clonogenic ability, especially at 10 μM and 20 μM (P < 0.01). Invasiveness decreased by 68.44 % at 5 μM (P < 0.05), and migration was significantly inhibited at 10 μM and 20 μM (P < 0.05). Western blot revealed increased E-cadherin and decreased Vimentin (P < 0.01), elevated β-catenin (P < 0.05), and reduced APC (P < 0.01). In summary, 1-NP impacts trophoblast cell clonogenicity, invasion, and migration by modulating EMT and Wnt/β-catenin pathways, providing novel insights into its biological effects on trophoblast cells.

Limiting Premenstrual Endometrial Hypoxia Inducible Factor 2 Alpha May Fine-Tune Endometrial Function at Menstruation

CONTEXT

Heavy menstrual bleeding (HMB) is common and debilitating, but the precise endometrial mechanisms causing increased menstrual blood loss (MBL) remain undefined. We have previously identified a role for hypoxia in endometrial repair following progesterone withdrawal.

OBJECTIVE

As hypoxia inducible factor 2 alpha (HIF2A) is known to alter vascular function in other tissues, we hypothezised that endometrial HIF2A is involved in premenstrual optimization of endometrial function during the secretory phase to limit MBL.

RESULTS

Women with objective HMB had higher endometrial HIF2A during the mid-secretory phase when compared to those with normal MBL (P = 0.0269). In a mouse model of simulated menses, genetic or pharmacological manipulation of HIF2A did not significantly affect endometrial breakdown/repair, volume of MBL or endometrial hypoxia. However, 88% of Hif2a heterozygote mice reached early-full repair by 24 hours vs only 65% of wild-type mice. Mean MBL was 0.39 μL (±0.67) in Hif2a heterozygote mice vs 0.98 μL (±0.79) in wild-type mice. Conversely, when we increased HIF2A before menstruation, 11% reached early repair by 8 hours vs 30% of vehicle-treated mice. Mean MBL was 2.61 μL (±1.10) in mice with HIF2A stabilization and 2.24 μL (±1.14) in vehicle-treated mice. These nonsignificant but consistent trends indicate that increased endometrial HIF2A may contribute to delayed endometrial repair and HMB.

CONCLUSIONS

Increased HIF2A in the secretory endometrium is unlikely to be sufficient to account for the phenotype of HMB, but limitation of HIF2 levels may optimize endometrial function at menstruation.

The effect of norethisterone acetate on the uterine telocytes, immune cells and progesterone receptors in albino rats

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.

Zearalenone enhances TSST-1 production by intestinal Staphylococcus and increases uterine immune stress in rats

Zearalenone (ZEA), a mycotoxin prevalent in food crops, poses significant health risks, particularly through its impact on the gut-uterus axis. This study assessed the effects of a 5 mg/kg body weight ZEA dosage in female SD rats, focusing on gut microbiota alterations, inflammatory responses, and uterine changes. Our findings revealed substantial shifts in microbial composition, including significant reductions in beneficial genera such as Akkermansia and Ruminococcaceae and marked increases in pathogenic staphylococci, which correlated with elevated levels of toxic shock syndrome toxin-1 (TSST-1) in serum and uterine tissue. RNA sequencing of uterine samples indicated activation of the extracellular matrix (ECM) pathway, along with significant upregulation of MMP-2 and TIMP-2, enzymes associated with ECM remodelling. Correlation analysis showed a strong link between staphylococcal proliferation and ECM pathway activation, suggesting that ZEA-induced gut dysbiosis contributes to uterine inflammation and structural alterations. These results reveal how ZEA disrupts gut and uterine health, highlighting critical pathways that could serve as targets for future preventive and therapeutic strategies against mycotoxin exposure.

Potential mechanisms for chorioamniotic membrane rupture after subchorionic hematoma

BACKGROUND

Subchorionic hematoma is a risk factor for preterm prelabor rupture of membranes and preterm birth. A small proportion of persistent subchorionic hematoma leads to a chronic abruption-oligohydramnios sequence.

OBJECTIVE

To determine the mechanism by which subchorionic hematomas may damage chorioamniotic membranes.

STUDY DESIGN

1) The number and subtype of macrophages were determined by immunohistochemistry in chorioamniotic membranes from 8 subchorionic hematoma patients who delivered preterm (25.5 (24-32) weeks of gestation (median and range)) and 6 gestational age-matched control patients (25.5 (25-28) weeks of gestation (median and range)). Further, the thickness and fibrosis of the membranes were quantified. 2) We also developed an intrauterine hematoma model in pregnant mice, and the effects of hematoma on the amnion were analyzed by histology and immunofluorescence. 3) In vitro, primary human amnion mesenchymal cells were cocultured with M2-differentiated macrophages, and changes in mesenchymal cells were analyzed.

RESULTS

1) Subchorionic hematoma increased the number of iron-laden macrophages in the human amnion. These macrophages were CD206+, a marker of macrophages required for the maintenance of homeostasis, tissue remodeling, and metabolic adaptations. The collagen layer of the amnion tended to be thickened in patients with subchorionic hematoma. Interestingly, α-smooth muscle actin+ myofibroblasts were increased in the amnion mesenchymal layer in patients with subchorionic hematoma. Vimentin, a mesenchymal marker, was expressed in the epithelial layer of the hematoma amnion. Together, these findings indicate epithelial-mesenchymal transition in the amnion of membranes from pregnancies with subchorionic hematomas. 2) These findings in human amnion were confirmed in a mouse model of intrauterine hematoma. 3) Further, in vitro, coculture of human amnion mesenchymal cells with M2-differentiated human macrophages resulted in transformation of these cells into α-smooth muscle actin-expressing myofibroblasts via the TGF-β‒Smad3 pathway.

CONCLUSION

Subchorionic hematoma induces migration of macrophages to chorioamniotic membranes which activate the transition of amnion mesenchymal cells to myofibroblasts. These myofibroblasts may contribute to fibrosis of the amnion and damage chorioamniotic membranes.

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.

No improvement in pregnancy and perinatal outcomes with combined luteal support in modified natural cycle frozen embryo transfer

Objective

We investigated whether the addition of a luteal phase support drug benefits pregnancy and perinatal outcomes in modified natural-cycle frozen-thawed embryo transfer (mNC-FET) for women up to the age of 35 years.

Methods

We analyzed the clinical data of 3658 mNC-FET cycles of women up to the age of 35 years from the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2018 to December 2020 in a retrospective cohort study. The cycles were divided into three groups based on the luteal phase support protocol used. The patients in group A received a combination of progesterone soft capsules and dydrogesterone (882 cycles), those in group B received dydrogesterone only (627 cycles), and those in group C received a combination of progesterone vaginal sustained-release gel and dydrogesterone (2149 cycles). Pregnancy and perinatal outcomes were compared among the three groups.

Results

Logistic regression analysis indicated that the three luteal phase support regimens were not associated with the live birth rate [OR(95% CI)B vs A=1.080, p=0.960; OR(95% CI)B vs C=0.252, p=0.291]. There were no significant differences in the newborn weight, premature delivery rate, pregnancy complications rate, and incidence of birth defects among the three groups.

Conclusions

In the mNC-FET cycle, patients under the age of 35 who chose dydrogesterone alone as a luteal phase support drug exhibited no difference in the live birth rate and perinatal outcome from patients who combined dydrogesterone with progesterone soft capsules or with progesterone vaginal sustained-release gel. However, the outcome still requires confirmation by large-sample prospective studies.

PAI-1 promotes human endometrial stromal decidualization via inhibiting VEGFR2/PI3K/AKT signaling pathway mediated F-actin reorganization

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.

Mitochondria remodeling during endometrial stromal cell decidualization

Upon hormonal stimulation, uterine endometrial stromal cells undergo a dramatic morpho-functional metamorphosis that allows them to secrete large amounts of matrix proteins, cytokines, and growth factors. This step, known as decidualization, is crucial for embryo implantation. We previously demonstrated how the secretory pathway is remodelled during this process. Here we show that hormonal stimulation rapidly induces the expression of many mitochondrial genes, encoded in both the mitochondrial and the nuclear genomes. Altogether, the mitochondrial network quadruples its size and establishes more contacts with the ER. This new organization results in the increased respiratory capacity of decidualized cells. These findings reveal how achieving an efficient secretory phenotype requires a radical metabolic rewiring.

Obstetric and Perinatal Outcomes in 44,118 Singleton Pregnancies: Endometrial Preparation Methods for Frozen-Thawed Embryo Transfer

BACKGROUND

This study aimed to investigate the obstetric and perinatal outcomes of singleton deliveries following frozen embryo transfer (FET) cycles using different endometrial preparation methods.

METHODS

We analyzed data on 44,118 singleton pregnant women who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI), resulting in delivery or abortion, from the South Korean National Health Insurance Service database. Stratification was based on the type of embryo transfer, viz. fresh embryo transfer and FET cycles, using International Classification of Diseases (Tenth Revision) diagnostic codes, national procedural codes, and prescription medication data within the IVF/ICSI pregnancy cohort. FET was subcategorized into artificial cycle-FET (AC-FET), natural cycle-FET (NC-FET), and stimulated cycle-FET (SC-FET) for comparative analyses of the pregnancy, obstetric, and perinatal outcomes.

RESULTS

AC-FET was associated with higher risks of hypertensive disorders of pregnancy, preeclampsia, placenta accreta, and postpartum hemorrhage compared with NC-FET; the risk of macrosomia showed no significant differences. SC-FET was associated with a lower risk of miscarriage and higher rate of term birth beyond 37 weeks compared with NC-FET. However, SC-FET was associated with elevated risks of gestational hypertension and postpartum hemorrhage when compared to NC-FET.

CONCLUSION

The rate of adverse obstetric and perinatal outcomes was higher in AC-FET compared to NC-FET, highlighting NC-FET as a valuable option owing to better maternal and fetal safety. In cases where NC-FET is not feasible, SC-FET presented as a favorable alternative, exhibiting lower miscarriage rates than NC-FET and better obstetric outcomes than AC-FET.

Cell-cycle machinery is critical in regulating uterine steroid hormone for embryo implantation and development

Proper embryo implantation is necessary for a successful pregnancy. In this issue of the JCI, Aljubran et al. identified the cell cycle regulatory protein cyclin A2 (CCNA2) as a factor in supporting embryo implantation and embryo development. Endometrial stromal cells showed higher levels of CCNA2 in patients undergoing assisted reproductive technology who had successful pregnancies. CCNA2 expression correlated with stromal cell proliferation and the expression of steroid hormone receptors for estrogen (ESR1, also known as ERα) and progesterone (PGR). Notably, loss of Ccna2 in mouse models resulted in infertility. The uteri of these mice were hypoplastic with reduced estrogen sensitivity, resulting in the disruption of stroma cell decidualization and loss of embryo viability after implantation. These findings demonstrate the importance of stroma cell proliferation in preparing the uterus for embryo implantation. They also identify CCNA2 as a coregulator of steroid hormone receptor signaling and suggest that impaired uterine stroma can underly early pregnancy loss.

Unfavorably Altered Fibrin Clot Phenotype in Women Following Postpartum Hemorrhage of Unknown Cause: Effect of Lower Coagulation Factors

BACKGROUND

 Increased clot permeability and susceptibility to lysis have been reported in women with heavy menstrual bleeding. We hypothesized that similar alterations in fibrin clot properties may also be present in women with postpartum hemorrhage (PPH) of unknown cause.

OBJECTIVE

 To determine fibrin clot properties and their determinants in women after PPH of unknown cause.

METHODS

 We studied 52 consecutive women, aged 35 years (27-40), after at least 3 months since PPH of unknown cause and 52 matched controls for age, weight, and fibrinogen. Coagulation factors (F), antithrombin, thrombin generation, along with a comprehensive plasma fibrin clot analysis including fibrin polymerization, clot permeability (K s), and fibrinolysis efficiency were determined.

RESULTS

 Women with PPH showed reduced activity of FII (-10.3%), FV (-6.6%), FIX (-6.5%), FX (-7.2%), and FXI (-5.7%) compared with the controls, though all values were within ranges (all p < 0.05). There were no intergroup differences in fibrinogen, FVIII, FXIII, and thrombin generation. The PPH group formed with a delay looser plasma fibrin network (K s; +16.3%, p = 0.008) with lower maximum absorbance and shorter clot lysis time (CLT; -13.5%, p = 0.001) compared with the controls. On multivariable logistic regression, PPH was independently associated with higher C-reactive protein (per 1 mg/L, odds ratio [OR] = 1.70, 95% confidence interval [CI]: 1.09-2.68), lower FII (per 1%, OR = 0.93, 95% CI: 0.89-0.98), lower FV (per 1%, OR = 0.93, 95% CI: 0.89-0.97), and shorter CLT (per 1 minute, OR = 0.94, 95% CI: 0.90-0.98).

CONCLUSION

 Prohemorrhagic fibrin clot properties, with lower, though normal coagulation factors, characterize women with PPH of unknown cause, which suggests novel mechanisms contributing to this type of bleeding.

Differences in perinatal complications and serum hormone levels due to uterine endometrial preparation methods in frozen-thawed embryo transfer

AIM

In frozen-thawed embryo transfer (FET), differences in endometrial preparation methods affect the incidence of perinatal complications. However, the underlying causes are unclear. We aimed to investigate whether serum E2, P4 levels are associated with perinatal complications.

METHODS

This is a retrospective cohort study, involving 306 successful FET pregnancies from 2017 to 2022. Participants were divided into Natural Cycle (NC) and Hormone Replacement Cycle (HRC) group. We compared serum hormone levels, maternal backgrounds, and perinatal outcomes and complications. Furthermore, within the HRC group, serum hormone levels were compared for perinatal complications previously reported to show differences in incidence rates depending on the method of endometrial preparation.

RESULTS

HRC exhibited significantly higher serum E2 levels during the implantation period, but lower P4 levels during ovulation, implantation, and pregnancy test period compared with NC. HRC also had significantly higher rates of postpartum hemorrhage (PPH) and placenta accreta spectrum (PAS). There was no association found between perinatal complications more likely to occur in HRC and serum E2, P4 levels.

CONCLUSIONS

In HRC, there were more occurrences of PPH and PAS. Although serum E2, P4 levels during FET did not correlate with perinatal complications.

Uterine cyclin A2-deficient mice as a model of female early pregnancy loss

Proper action of the female sex steroids 17β-estradiol (E2) and progesterone (P4) on the endometrium is essential for fertility. Beyond its role in regulating the cell cycle, cyclin A2 (CCNA2) also mediates E2 and P4 signaling in vitro, but a potential role in modulating steroid action for proper endometrial tissue development and function is unknown. To fill this gap in our knowledge, we examined human endometrial tissue from fertile and infertile cisgender women for CCNA2 expression and correlated this with pregnancy outcome. Functional assessment of CCNA2 was validated in vivo using a conditional Ccna2 uterine-deficient mouse model, while in vitro function was assessed using human cell culture models. We found that CCNA2 expression was significantly reduced in endometrial tissue, specifically the stromal cells, from women undergoing in vitro fertilization who failed to achieve pregnancy. Conditional deletion of Ccna2 from mouse uterine tissue resulted in an inability to achieve pregnancy, which appeared to be due to alterations in the process of decidualization, which was confirmed using in vitro models. From these studies, we conclude that CCNA2 expression during the proliferative/regenerative stage of the menstrual cycle allows for proper steroid responsiveness, decidualization, and pregnancy. When CCNA2 expression levels are insufficient, there is impaired endometrial responsiveness, aberrant decidualization, and loss of pregnancy.

Decreased AMPK/SIRT1/PDK4 induced by androgen excess inhibits human endometrial stromal cell decidualization in PCOS

Polycystic ovary syndrome (PCOS) is a complex common endocrine disorder affecting women of reproductive age. Ovulatory dysfunction is recognized as a primary infertile factor, however, even when ovulation is medically induced and restored, PCOS patients continue to experience reduced cumulative pregnancy rates and a higher spontaneous miscarriage rate. Hyperandrogenism, a hallmark feature of PCOS, affects ovarian folliculogenesis, endometrial receptivity, and the establishment and maintenance of pregnancy. Decidualization denotes the transformation that the stromal compart of the endometrium must undergo to accommodate pregnancy, driven by the rising progesterone levels and local cAMP production. However, studies on the impact of hyperandrogenism on decidualization are limited. In this study, we observed that primary endometrial stromal cells from women with PCOS exhibit abnormal responses to progesterone during in vitro decidualization. A high concentration of testosterone inhibits human endometrial stromal cells (HESCs) decidualization. RNA-Seq analysis demonstrated that pyruvate dehydrogenase kinase 4 (PDK4) expression was significantly lower in the endometrium of PCOS patients with hyperandrogenism compared to those without hyperandrogenism. We also characterized that the expression of PDK4 is elevated in the endometrium stroma at the mid-secretory phase. Artificial decidualization could enhance PDK4 expression, while downregulation of PDK4 leads to abnormal decidualization both in vivo and in vitro. Mechanistically, testosterone excess inhibits IGFBP1 and PRL expression, followed by phosphorylating of AMPK that stimulates PDK4 expression. Based on co-immunoprecipitation analysis, we observed an interaction between SIRT1 and PDK4, promoting glycolysis to facilitate decidualization. Restrain of AR activation resumes the AMPK/SIRT1/PDK4 pathway suppressed by testosterone excess, indicating that testosterone primarily acts on decidualization through AR stimulation. Androgen excess in the endometrium inhibits decidualization by disrupting the AMPK/SIRT1/PDK4 signaling pathway. These data demonstrate the critical roles of endometrial PDK4 in regulating decidualization and provide valuable information for understanding the underlying mechanism during decidualization.

Investigating Menstruation and Adverse Pregnancy Outcomes: Oxymoron or New Frontier? A Narrative Review

Not discounting the important foetal or placental contribution, the endometrium is a key determinant of pregnancy outcomes. Given the inherently linked processes of menstruation, pregnancy and parturition with the endometrium, further understanding of menstruation will help to elucidate the maternal contribution to pregnancy. Endometrial health can be assessed via menstrual history and menstrual fluid, a cyclically shed, easily and non-invasively accessible biological sample that represents the distinct, heterogeneous composition of the endometrial environment. Menstrual fluid has been applied to the study of endometriosis, unexplained infertility and early pregnancy loss; however, it is yet to be examined regarding adverse pregnancy outcomes. These adverse outcomes, including preeclampsia, foetal growth restriction (FGR), spontaneous preterm birth and perinatal death (stillbirth and neonatal death), lay on a spectrum of severity and are often attributed to placental dysfunction. The source of this placental dysfunction is largely unknown and may be due to underlying endometrial abnormalities or endometrial interactions during placentation. We present existing evidence for the endometrial contribution to adverse pregnancy outcomes and propose that a more comprehensive understanding of menstruation can provide insight into the endometrial environment, offering great potential value as a diagnostic tool to assess pregnancy risk. As yet, this concept has hardly been explored.

Prenatal exposure to Benzo[a]pyrene affects maternal-fetal outcomes via placental apoptosis

Prenatal exposure to Benzo[a]pyrene (BaP) has been suggested to increase the risk of adverse pregnancy outcomes. However, the role of placental apoptosis on BaP reproductive toxicity is poorly understood. We conducted a maternal animal model of C57BL/6 wild-type (WT) and transformation-related protein 53 (Trp53) heterozygous knockout (p53KO) mice, as well as a nested case-control study involving 83 women with PB and 82 term birth from a birth cohort on prenatal exposure to BaP and preterm birth (PB). Pregnant WT and p53KO mice were randomly allocated to BaP treatment and control groups, intraperitoneally injected of low (7.8 mg/kg), medium (35 mg/kg), and high (78 mg/kg) doses of 3,4-BaP per day and equal volume of vegetable oil, from gestational day 10.5 until delivery. Results show that high-dose BaP treatment increased the incidence of preterm birth in WT mice. The number of fetal deaths and resorptions increased with increasing doses of BaP exposure in mice. Notably, significant reductions in maternal and birth weights, increases in placental weights, and decrease in the number of livebirths were observed in higher-dose BaP groups in dose-dependent manner. We additionally observed elevated p53-mediated placental apoptosis in higher BaP exposure groups, with altered expression levels of p53 and Bax/Bcl-2. In case-control study, the expression level of MMP2 was increased among women with high BaP exposure and associated with the increased risk of all PB and moderate PB. Our study provides the first evidence of BaP-induced reproductive toxicity and its adverse effects on maternal-fetal outcomes in both animal and population studies.

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.

A Novel Method to Repair Thin Endometrium and Restore Fertility Based on Menstruation-Derived Stem Cell

Thin endometrium (TE), which mainly occurs as a result of severe damage to the endometrial basalis, is one of the prominent etiologies of menstrual abnormalities, infertility, and recurrent miscarriage in women. Previous studies have demonstrated that mesenchymal stem cells (MSCs) are considered ideal cells with multipotency for regenerative medicine and exhibit therapeutic effects on TE through their cellular secretions. However, there is limited research on strategies to enhance MSC secretion to improve their therapeutic efficacy. Herein, we isolated menstrual blood-derived mesenchymal stem cells (MenSCs) from menstruation and transformed them into decidualized stromal cells (DSCs), which are specialized cells with enhanced secretory functions. To assess the therapeutic potential of DSCs compared to MenSCs, we conducted a series of experiments in cells and animals. The results demonstrated that DSCs exhibited changes in morphology compared to MenSCs, with a decrease in cell proliferation but a significant improvement in secretion function. Furthermore, DSCs facilitated the restoration of endometrial thickness and increased the number of glands and blood vessel formation. Most importantly, the pregnancy rates in rats were effectively restored, bringing them closer to normal levels. These findings greatly contribute to our understanding of stem cell therapy for TE and strongly suggest that DSCs could hold significant promise as a potential treatment option for TE.

Interleukin-1 beta signals through the ERK signalling pathway to modulate human placental trophoblast migration and invasion in the first trimester of pregnancy

INTRODUCTION

Interleukin-1 beta (IL-1β) can promote cell migration, invasion and metastasis in various cancer cells. The mechanism of its role in human trophoblast has not been fully investigated. Therefore, we aimed to investigate the expression level of IL-1β in first trimester decidua and placenta and its potential role in regulation of extravillous trophoblast cell (EVT) invasion and migration.

METHODS

First trimester placenta and decidua were collected to study the expression levels of IL-1β and its receptors by immunohistochemical staining. Primary isolates of first trimester EVT or the HTR-8/SVneo trophoblast like cell line were used to assess migration and invasion. Matrix metalloproteinase levels were assessed by gelatin zymography and ELISA. The phosphorylation profile of signaling pathway proteins was detected with the Proteome Profiler Human Phospho-Kinase Array Kit. Differentially expressed proteins in cells was detected and verified by Western Blot.

RESULTS

IL-1β, its receptors and antagonist are expressed in first trimester placenta and decidua, exogenous IL-1β stimulates trophoblast cell outgrowth, migration and invasion through the ERK signaling pathway. IL-1β was significantly increased in the placenta at 6-7 weeks gestation compared with 8-9 weeks gestation (P < 0.0001). Transwell and RTCA assays indicated that IL-1β stimulates the invasion and migration of EVT. In addition, IL-1β promoted the phosphorylation of ERK 1/2. It also promoted the expression of MMP2 and MMP9 in EVT as demonstrated by gelatin zymography assay and enzyme linked immunosorbent assay.

DISCUSSION

This study demonstrated IL-1β expression in placenta and decidua, and that it regulates EVT invasion and migration.

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.

COVID-19 (SARS-CoV-2) mRNA vaccination does not affect basal sex hormone levels (follicle-stimulating hormone, luteinizing hormone, estradiol) in reproductive-age women

OBJECTIVE

People vaccinated with the coronavirus disease 2019 (COVID-19) (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) mRNA vaccine have reported experiencing various adverse effects. For instance, reproductive-age women have presented with complaints of abnormal uterine bleeding or menstrual cycle changes. We speculated that differences in basal sex hormone levels before and after vaccination may be present in women who experienced irregular bleeding or menstrual cycle changes; thus, this study aimed to investigate the differences in basal sex hormone levels of women before and after two doses of SARS-CoV-2 mRNA vaccination.

METHODS

This retrospective study included patients who received SARS-CoV-2 mRNA vaccines between January 2021 and February 2022 at a single center. In an outpatient setting, patients were queried regarding their menstrual cycle, the date of SARS-CoV-2 mRNA vaccination, vaccination type, and vaccination side effects. Differences in basal hormone levels (menstrual cycle days 2-3, follicle-stimulating hormone [FSH], luteinizing hormone [LH], and estradiol) before and after vaccination were compared.

RESULTS

Among the 326 patients, patients with no laboratory records of the hormones were excluded. The median time interval between SARS-CoV-2 mRNA vaccination and the laboratory test day was 79 days (interquartile range, 44 to 127). A comparative analysis of these hormones before and after vaccination revealed no significant differences. Subgroup analyses based on age and reported adverse events also found no statistically significant differences.

CONCLUSION

This study showed no significant differences in basal hormone levels (FSH, LH, and estradiol) before and after SARS-CoV-2 mRNA vaccination.

Subacute exposure to DEHP leads to impaired decidual reaction and exacerbates the risk of early miscarriage in mice

OBJECTIVES

To investigate the effect of subacute exposure of Di (2-ethylhexyl) phthalate (DEHP) on endometrial decidualization and early pregnancy miscarriage in mice.

METHODS

CD1 mice were orally administrated with 300 (low-dose group), 1000 (medium-dose group), or 3000 mg·kg－1·d－1 DEHP (1/10 LD50, high-dose group) for 28 days, respectively. An early natural pregnancy model and an artificially induced decidualization model were established. The uterine tissues were collected on D7 of natural pregnancy and D8 of artificially induced decidualization, respectively. The effects of a subacute exposure to DEHP on the decidualization of mice were detected by HE staining, Masson staining, TUNEL assay, and Western blotting. A model of spontaneous abortion was constructed in mice after subacute exposure to 300 mg·kg－1·d－1 DEHP, and the effect of impaired decidualization on pregnancy was investigated by observing the pregnancy outcome on the 10th day of gestation.

RESULTS

Compared with the control group, the conception rate was significantly decreased in the high-dose DEHP subacute exposure group (P<0.05). HE staining showed that, compared with the control group, the decidual stromal cells in the low- and medium-dose exposure groups were disorganized, the nuclei of the cells were irregular, the cytoplasmic staining was uneven, and the number of polymorphonuclear cells was significantly reduced. Masson staining showed that compared with the control group, the collagen fibers in the decidua region of the DEHP low-dose group and the medium-dose group were more distributed, more abundant and more disorderly. TUNEL assay showed increased apoptosis in the decidua area compared to the control group. Western blotting showed that the expression of BMP2, a marker molecule for endometrial decidualization, was significantly reduced (P<0.05 or P<0.01). The abortion rate and embryo resorption rate were increased, and the number of embryos, uterine wet weight, uterine area and placenta wet weight were decreased in DEHP low-dose group compared to the control group stimulated by mifepristone, an abortifacient drug (P<0.05 or P<0.01).

CONCLUSIONS

Subacute exposure to DEHP leads to impaired endometrial decidualization during early pregnancy and exacerbates the risk of adverse pregnancy outcomes in mice.

Beyond Immune Balance: The Pivotal Role of Decidual Regulatory T Cells in Unexplained Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal-fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal-fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.

Gamma delta (γδ) T cells in the female reproductive tract: active participants or indifferent bystanders in reproductive success?

The female reproductive tract accommodates and balances the unique immunological challenges of protection from sexually transmitted pathogens and tolerance of the fetus and placenta in pregnancy. Leukocytes in the female reproductive tract actively engage in extensive maternal adaptations that are imperative for embryo implantation, placental development, and fetal growth support. γδ T cells are abundant at many mucosal sites in the body, where they provide protection against pathogens and cancer, and have roles in tissue renewal and homeostasis. In this review, we summarize studies in humans and rodents showing that γδ T cells are prevalent in the female reproductive tract and fluctuate in response to hormone changes across the reproductive cycle. Emerging evidence points to a link between changes in their abundance and molecular repertoire in the uterus and pregnancy disorders including recurrent miscarriage and preterm birth. However, defining the precise functional role of female reproductive tract γδ T cells and understanding their physiological significance in reproduction and pregnancy have remained elusive. Here, we critically analyze whether reproductive tract γδ T cells could be active participants in reproductive events-or whether their principal function is immune defense, in which case they may compromise pregnancy success unless adequately regulated.

Single-cell transcriptome analyses reveal disturbed decidual homoeostasis in obstetric antiphospholipid syndrome

OBJECTIVES

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disease characterised by the presence of antiphospholipid antibodies in circulation and pathological pregnancy. However, the pathogenesis of OAPS remains unknown. We aimed to reveal cellular compositions and molecular features of decidual cells involved in the development of OAPS using single-cell RNA sequencing (scRNA-seq).

METHODS

We performed unbiased scRNA-seq analysis on the first-trimester decidua from five OAPS patients and five healthy controls (HCs), followed by validations with flow cytometry, immunohistochemical staining and immunofluorescence in a larger cohort. Serum chemokines and cytokines were measured by using ELISA.

RESULTS

A higher ratio of macrophages but a lower ratio of decidual natural killer (dNK) cells was found in decidua from OAPS compared with HCs. Vascular endothelial cells shrinked in OAPS decidua while having upregulated chemokine expression and conspicuous responses to IFN-γ and TNF-α. Macrophages in OAPS had stronger phagocytosis function, complement activation signals and relied more on glycolysis. dNK cells were more activated in OAPS and had enhanced cytotoxicity and IFN-γ production. Downregulation of granules in OAPS dNK cells could be associated with suppressed glycolysis. Moreover, stromal cells had a prosenescent state with weakened immune surveillance for senescent cells in OAPS. In addition, the cellular interactions between decidual immune cells and those of immune cells with non-immune cells under disease state were altered, especially through chemokines, IFN-γ and TNF-α.

CONCLUSION

This study provided a comprehensive decidual cell landscape and identified aberrant decidual microenvironment in OAPS, providing some potential therapeutic targets for this disease.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Decidual leukocytes respond to African lineage Zika virus infection with mild anti-inflammatory changes during acute infection in rhesus macaques

Zika virus (ZIKV) can be vertically transmitted during pregnancy resulting in a range of adverse pregnancy outcomes. The decidua is commonly found to be infected by ZIKV, yet the acute immune response to infection remains understudied in vivo. We hypothesized that in vivo African-lineage ZIKV infection induces a pro-inflammatory response in the decidua. To test this hypothesis, we evaluated the decidua in pregnant rhesus macaques within the first two weeks following infection with an African-lineage ZIKV and compared our findings to gestationally aged-matched controls. Decidual leukocytes were phenotypically evaluated using spectral flow cytometry, and cytokines and chemokines were measured in tissue homogenates from the decidua, placenta, and fetal membranes. The results of this study did not support our hypothesis. Although ZIKV RNA was detected in the decidual tissue samples from all ZIKV infected dams, phenotypic changes in decidual leukocytes and differences in cytokine profiles suggest that the decidua undergoes mild anti-inflammatory changes in response to that infection. Our findings emphasize the immunological state of the gravid uterus as a relatively immune privileged site that prioritizes tolerance of the fetus over mounting a pro-inflammatory response to clear infection.

CD24+ decidual stromal cells: a novel heterogeneous population with impaired regulatory T cell induction and potential association with recurrent miscarriage

OBJECTIVE

To explore the heterogeneity of CD24+ decidual stromal cells (DSCs) in patients with recurrent miscarriages (RMs).

DESIGN

We have discerned that the expression of CD24 serves to differentiate two stable and functionally distinct lineages of DSCs. The heterogeneity of CD24+ DSCs has been scrutinized, encompassing variances in stromal markers, transcriptional profiles, metabolic activity, and immune regulation.

SETTING

Department of Reproductive Immunology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University; Shanghai Institute of Immunity and Infection, Chinese Academy of Science.

PATIENTS

A total of 129 early decidual samples were obtained, comprising 36 from healthy donors and 93 from patients with RMs. Blood samples were collected before the surgical procedure. Paraffin-embedded segments from 20 decidual samples of patients with RMs were obtained.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The flow cytometry was used to quantify the expression of CD24+ DSCs in both healthy donors and patients with RMs, although it also evaluated the cellular heterogeneity. To ascertain the transcriptomic profiles of CD24+ DSCs by reanalyzing our single-cell transcriptomic data. Additionally, to measure the metabolomic activity of CD24+ DSCs from patients with RMs, ultraperformance liquid chromatography-mass spectrometry was employed. Through the implementation of a coculture system, we unraveled the role of CD24+ DSCs in immune regulation.

RESULTS

Patients with RMs exhibit a notable enrichment of CD24+ DSCs, revealing a pronounced heterogeneity characterized by variations in stromal markers and transcriptional profiles. The heightened enrichment of CD24+ DSCs may play a pivotal role in triggering decidual inflammation and dysfunction in decidualization. Furthermore, CD24+ DSCs showed diverse metabolic activities and impeded the induction of naïve CD4+ T cells into regulatory T cells through the abundant secretion of 3-hydroxyisovaleric acid. Finally, our investigations have revealed that intraperitoneal administration of 3-hydroxyisovaleric acid in mouse models can elevate the risk of RM.

CONCLUSION

We have successfully identified a disease-associated subset of CD24+ decidual stromal cells that could potentially contribute to the development of RM through the impairment of decidual immune tolerance. Targeting these specific CD24+ DSCs might hold promising prospects for therapeutic interventions in the clinical management of RM.

Kobayashi E, Oike A, Kobayashi N, Kitamura A, Hori T, Nashimoto Y, Nakato R, Hamada H, Kaji H, Kikutake C, Suyama M, Saito M, Yaegashi N, Okae H, Arima T. Modeling embryo-endometrial interface recapitulating human embryo implantation

The initiation of human pregnancy is marked by the implantation of an embryo into the uterine environment; however, the underlying mechanisms remain largely elusive. To address this knowledge gap, we developed hormone-responsive endometrial organoids (EMO), termed apical-out (AO)-EMO, which emulate the in vivo architecture of endometrial tissue. The AO-EMO comprise an exposed apical epithelium surface, dense stromal cells, and a self-formed endothelial network. When cocultured with human embryonic stem cell-derived blastoids, the three-dimensional feto-maternal assembloid system recapitulates critical implantation stages, including apposition, adhesion, and invasion. Endometrial epithelial cells were subsequently disrupted by syncytial cells, which invade and fuse with endometrial stromal cells. We validated this fusion of syncytiotrophoblasts and stromal cells using human blastocysts. Our model provides a foundation for investigating embryo implantation and feto-maternal interactions, offering valuable insights for advancing reproductive medicine.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Predictors and perinatal outcomes of pre-labor rupture of membrane among pregnant women admitted to Hiwot Fana Comprehensive Specialized University Hospital, Eastern Ethiopia: a retrospective study

Background

Pre-labor rupture of membrane (PROM) refers to a membrane rupture that occurs after the 28th week of pregnancy but before the start of labor. If not appropriately managed, it poses a significant risk to the health of the mother and fetus. However, information on the magnitude of PROM, contributing factors, and its perinatal outcomes was limited in Eastern Ethiopia. This study assessed the prevalence, predictors, and perinatal outcomes of PROM among pregnant women admitted to Hiwot Fana Comprehensive Specialized University Hospital (HFCSUH) in Eastern Ethiopia so as to guide specific preventive measures.

Methods

A hospital-based retrospective cross-sectional study was carried out from May 15 to June 14, 2022, and data were gathered by reviewing the chart records of 424 pregnant women who were admitted to maternity and labor wards in the previous two years, from January 1, 2019 to December 31, 2020. Records were chosen using a simple random sampling method. Mother's socio-demographic traits, previous obstetric and gynecologic history, current pregnancy history, habit-related history (khat chewing), ultrasound findings, laboratory investigations, mode of delivery, maternal and perinatal outcomes were extracted from the maternal charts. Bi-variable and multivariable logistic regression analyses were performed to identify predictors of pre-labor membrane rupture. The association between the explanatory and outcome variables was expressed using an adjusted odds ratio with a 95% confidence interval.

Results

The prevalence of pre-labor membrane rupture was 16.27% with 95% CI: (13.05-20.11). Among 69 women who experienced pre-labor rupture of membrane, 50 (72.5%) of them had adverse perinatal outcomes. Of all 69 neonates 17 (24.64%) were delivered with low birth weight and 20 (29%) of them were born preterm. The overall perinatal mortality rate was 10.1% or 101 per 1,000 live births. History of abortion [AOR = 2.61; 95% CI (1.09, 6.24)], urinary tract infection [AOR = 2.59; 95% CI (1.23, 5.42)], antepartum hemorrhage [AOR = 3.35; 95% CI (1.38, 8.13)], and khat chewing (a leafy plant which contains psychoactive chemical) in the current pregnancy [AOR = 2.63; 95% CI (1.49, 4.63)] were all significantly associated with pre-labor rupture of membrane.

Conclusion

In this study, the magnitude of pre-labor membrane rupture was relatively high compared to the global rate. Prenatal risk identification and early detection of complications among mothers with a history of abortion, antepartum hemorrhage, urinary tract infection, and counseling on the effects of khat chewing during pregnancy are crucial to reduce the likelihood of pre-labor membrane rupture and its adverse perinatal outcome.

Macrophage plasticity and function in cancer and pregnancy

As the soil of life, the composition and shaping process of the immune microenvironment of the uterus is worth exploring. Macrophages, indispensable constituents of the innate immune system, are essential mediators of inflammation and tissue remodeling as well. Recent insights into the heterogeneity of macrophage subpopulations have renewed interest in their functional diversity in both physiological and pathological settings. Macrophages display remarkable plasticity and switch from one phenotype to another. Intrinsic plasticity enables tissue macrophages to perform a variety of functions in response to changing tissue contexts, such as cancer and pregnancy. The remarkable diversity and plasticity make macrophages particularly intriguing cells given their dichotomous role in either attacking or protecting tumors and semi-allogeneic fetuses, which of both are characterized functionally by immunomodulation and neovascularization. Here, we reviewed and compared novel perspectives on macrophage biology of these two settings, including origin, phenotype, differentiation, and essential roles in corresponding microenvironments, as informed by recent studies on the heterogeneity of macrophage identity and function, as well as their mechanisms that might offer opportunities for new therapeutic strategies on malignancy and pregnancy complications.

Maternal exposure to nano-titanium dioxide impedes fetal development via endothelial-to-mesenchymal transition in the placental labyrinth in mice

BACKGROUND

Extensive production and usage of commercially available products containing TiO2 NPs have led to accumulation in the human body. The deposition of TiO2 NPs has even been detected in the human placenta, which raises concerns regarding fetal health. Previous studies regarding developmental toxicity have frequently focused on TiO2 NPs < 50 nm, whereas the potential adverse effects of large-sized TiO2 NPs received less attention. Placental vasculature is essential for maternal-fetal circulatory exchange and ensuring fetal growth. This study explores the impacts of TiO2 NPs (100 nm in size) on the placenta and fetal development and elucidates the underlying mechanism from the perspective of placental vasculature. Pregnant C57BL/6 mice were exposed to TiO2 NPs by gavage at daily dosages of 10, 50, and 250 mg/kg from gestational day 0.5-16.5.

RESULTS

TiO2 NPs penetrated the placenta and accumulated in the fetal mice. The fetuses in the TiO2 NP-exposed groups exhibited a dose-dependent decrease in body weight and length, as well as in placental weight and diameter. In vivo imaging showed an impaired placental barrier, and pathological examinations revealed a disrupted vascular network of the labyrinth upon TiO2 NP exposure. We also found an increase in gene expression related to the transforming growth factor-β (TGF-β) -SNAIL pathway and the upregulation of mesenchymal markers, accompanied by a reduction in endothelial markers. In addition, TiO2 NPs enhanced the gene expression responsible for the endothelial-to-mesenchymal transition (EndMT) in cultured human umbilical vein endothelial cells, whereas SNAIL knockdown attenuated the induction of EndMT phenotypes.

CONCLUSION

Our study revealed that maternal exposure to 100 nm TiO2 NPs disrupts placental vascular development and fetal mice growth through aberrant activation of EndMT in the placental labyrinth. These data provide novel insight into the mechanisms of developmental toxicity posed by NPs.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Obstetric and neonatal outcomes after natural versus artificial cycle frozen embryo transfer and the role of luteal phase support: a systematic review and meta-analysis

BACKGROUND

The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when natural cycle FET (NC-FET) is compared to artificial cycle FET (AC-FET) in subfertile women. However, NC-FET seems to be associated with lower risk of adverse obstetric and neonatal outcomes compared with AC-FET cycles. Currently, there is no consensus about whether NC-FET needs to be combined with luteal phase support (LPS) or not. The question of how to prepare the endometrium for FET has now gained even more importance and taken the dimension of safety into account as it should not simply be reduced to the basic question of effectiveness.

OBJECTIVE AND RATIONALE

The objective of this project was to determine whether NC-FET, with or without LPS, decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET.

SEARCH METHODS

A systematic review and meta-analysis was carried out. A literature search was performed using the following databases: CINAHL, EMBASE, and MEDLINE from inception to 10 October 2022. Observational studies, including cohort studies, and registries comparing obstetric and neonatal outcomes between singleton pregnancies after NC-FET and those after AC-FET were sought. Risk of bias was assessed using the ROBINS-I tool. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. We calculated pooled odds ratios (ORs), pooled risk differences (RDs), pooled adjusted ORs, and prevalence estimates with 95% CI using a random effect model, while heterogeneity was assessed by the I2.

OUTCOMES

The conducted search identified 2436 studies, 890 duplicates were removed and 1546 studies were screened. Thirty studies (NC-FET n = 56 445; AC-FET n = 57 231) were included, 19 of which used LPS in NC-FET. Birthweight was lower following NC-FET versus AC-FET (mean difference 26.35 g; 95% CI 11.61-41.08, I2 = 63%). Furthermore NC-FET compared to AC-FET resulted in a lower risk of large for gestational age (OR 0.88, 95% 0.83-0.94, I2 = 54%), macrosomia (OR 0.81; 95% CI 0.71-0.93, I2 = 68%), low birthweight (OR 0.81, 95% CI 0.77-0.85, I2 = 41%), early pregnancy loss (OR 0.73; 95% CI 0.61-0.86, I2 = 70%), preterm birth (OR 0.80; 95% CI 0.75-0.85, I2 = 20%), very preterm birth (OR 0.66, 95% CI 0.53-0.84, I2 = 0%), hypertensive disorders of pregnancy (OR 0.60, 95% CI 0.50-0.65, I2 = 61%), pre-eclampsia (OR 0.50; 95% CI 0.42-0.60, I2 = 44%), placenta previa (OR 0.84, 95% CI 0.73-0.97, I2 = 0%), and postpartum hemorrhage (OR 0.43; 95% CI 0.38-0.48, I2 = 53%). Stratified analyses on LPS use in NC-FET suggested that, compared to AC-FET, NC-FET with LPS decreased preterm birth risk, while NC-FET without LPS did not (OR 0.75, 95% CI 0.70-0.81). LPS use did not modify the other outcomes. Heterogeneity varied from low to high, while quality of the evidence was very low to moderate.

WIDER IMPLICATIONS

This study confirms that NC-FET decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET. We estimate that for each adverse outcome, use of NC-FET may prevent 4 to 22 cases per 1000 women. Consequently, NC-FET should be the preferred treatment in women with ovulatory cycles undergoing FET. Based on very low quality of evidence, the risk of preterm birth be decreased when LPS is used in NC-FET compared to AC-FET. However, because of many uncertainties-the major being the debate about efficacy of the use of LPS-future research is needed on efficacy and safety of LPS and no recommendation can be made about the use of LPS.

Maternal Risk of Cardiovascular Disease After Use of Assisted Reproductive Technologies

Importance

The use of assisted reproductive technologies (ARTs) is steadily increasing worldwide. The outcomes associated with treatment for an individual's long-term health, including risk of cardiovascular disease (CVD), remain largely unknown, due to the small number of studies and their limited follow-up time.

Objective

To study whether the risk of CVD is increased among individuals who have given birth after ART compared with those who have given birth without ART.

Design, Setting, and Participants

A registry-based cohort study was conducted using nationwide data from Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015), and Sweden (1985-2015). Data analysis was conducted from January to August 2022. A total of 2 496 441 individuals with a registered delivery in the national birth registries during the study period were included, and 97 474 (4%) of these gave birth after ART.

Exposures

Data on ART conception were available from ART quality registries and/or medical birth registries.

Main Outcomes and Measures

Information on CVD was available from patient and cause of death registries. The risk of CVD was estimated with Cox proportional hazards regression, adjusting for age, calendar year of start of follow-up, parity, diagnosis of polycystic ovary syndrome, diabetes, chronic hypertension, and country.

Results

Median follow-up was 11 (IQR, 5-18) years. The mean (SD) age of women with no use of ART was 29.1 (4.9) years, and the age of those who used ART was 33.8 (4.7) years. The rate of any CVD was 153 per 100 000 person-years. Individuals who gave birth after using ART had no increased risk of CVD (adjusted hazard ratio [AHR], 0.97; 95% CI, 0.91-1.02), with evidence of heterogeneity between the countries (I2 = 76%; P = .01 for heterogeneity). No significant differences in the risk of ischemic heart disease, cerebrovascular disease, stroke, cardiomyopathy, heart failure, pulmonary embolism, or deep vein thrombosis were noted with use of ART. However, there was a tendency for a modest reduction in the risk of myocardial infarction (AHR, 0.80; 95% CI, 0.65-0.99), with no notable heterogeneity between countries.

Conclusions and Relevance

The findings of this study suggest that women who gave birth after ART were not at increased risk of CVD over a median follow-up of 11 years compared with those who conceived without ART. Longer-term studies are needed to further examine whether ART is associated with higher risk of CVD.

Endometrial Origins of Stillbirth (EOS), a case-control study of menstrual fluid to understand and prevent preterm stillbirth and associated adverse pregnancy outcomes: study protocol

INTRODUCTION

Current research aimed at understanding and preventing stillbirth focuses almost exclusively on the role of the placenta. The underlying origins of poor placental function leading to stillbirth, however, remain poorly understood. There is evidence demonstrating that the endometrial environment in which the embryo implants impacts not only the establishment of pregnancy but also the development of some pregnancy outcomes. Menstrual fluid has recently been applied to the study of menstrual disorders such as heavy menstrual bleeding or endometriosis, however, it has great potential in the study of adverse pregnancy outcomes. This study aims to identify differences in menstrual fluid and menstrual cycle characteristics of women who have experienced preterm stillbirth and other associated adverse pregnancy outcomes, compared with those who have not. The association between menstrual fluid composition and menstrual cycle characteristics will also be determined.

METHODS AND ANALYSIS

This is a case-control study of women who have experienced a late miscarriage, spontaneous preterm birth or preterm stillbirth or a pregnancy complicated by placental insufficiency (fetal growth restriction or pre-eclampsia), compared with those who have had a healthy term birth. Cases will be matched for maternal age, body mass index and gravidity. Participants will not currently be on hormonal therapy. Women will be provided with a menstrual cup and will collect their sample on day 2 of menstruation. Primary exposure measures include morphological and functional differences in decidualisation of the endometrium (cell types, immune cell subpopulations and protein composition secreted from the decidualised endometrium). Women will complete a menstrual history survey to capture menstrual cycle length, regularity, level of pain and heaviness of flow.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Monash University Human Research Ethics Committee (27900) on 14/07/2021 and will be conducted in accordance with these conditions. Findings from this study will be disseminated through peer-reviewed publications and conference presentations.

Angiogenesis in abnormal uterine bleeding: a narrative review

BACKGROUND

Abnormal uterine bleeding (AUB) has a significant socioeconomic impact since it considerably impacts quality of life. Therapeutic options are frequently based on trial and error and do not target disease aetiology. Pathophysiological insight in this disease is required for the development of novel treatment options. If no underlying cause is found for the AUB (e.g. fibroids, adenomyosis, polyps), endometrial-AUB (AUB-E) is usually caused by a primary endometrium disorder. When AUB is induced by prescribed (exogenous) hormones, it is classified as iatrogenic-AUB (AUB-I). Considering vascular modulation and function, AUB-E and AUB-I both could potentially result from abnormal vascularization in the endometrium due to alterations in the process of angiogenesis and vascular maturation.

OBJECTIVE AND RATIONALE

We aim to investigate the fundamental role of angiogenesis and vascular maturation in patients with AUB and hypothesize that aberrant endometrial angiogenesis has an important role in the aetiology of both AUB-E and AUB-I, possibly through different mechanisms.

SEARCH METHODS

A systematic literature search was performed until September 2021 in the Cochrane Library Databases, Embase, PubMed, and Web of Science, with search terms such as angiogenesis and abnormal uterine bleeding. Included studies reported on angiogenesis in the endometrium of premenopausal women with AUB-E or AUB-I. Case reports, letters, reviews, editorial articles, and studies on AUB with causes classified by the International Federation of Gynecology and Obstetrics as myometrial, oncological, or infectious, were excluded. Study quality was assessed by risk of bias, using the Cochrane tool and the Newcastle-Ottawa Scale.

OUTCOMES

Thirty-five out of 2158 articles were included. In patients with AUB-E, vascular endothelial growth factor A and its receptors (1 and 2), as well as the angiopoietin-1:angiopoietin-2 ratio and Tie-1, were significantly increased. Several studies reported on the differential expression of other pro- and antiangiogenic factors in patients with AUB-E, suggesting aberrant vascular maturation and impaired vessel integrity. Overall, endometrial microvessel density (MVD) was comparable in patients with AUB-E and controls. Interestingly, patients with AUB-I showed a higher MVD and higher expression of proangiogenic factors when compared to controls, in particular after short-term hormone exposure. This effect was gradually lost after longer-term exposure, while alterations in vessel maturation were observed after both short- and long-term exposures.

WIDER IMPLICATIONS

AUB-E and AUB-I are most likely associated with aberrant endometrial angiogenesis and impaired vessel maturation. This review supports existing evidence that increased proangiogenic and decreased antiangiogenic factors cause impaired vessel maturation, resulting in more fragile and permeable vessels. This matches our hypothesis and these mechanisms appear to play an important role in the pathophysiology of AUB-E and AUB-I. Exploring the alterations in angiogenesis in these patients could provide treatment targets for AUB.

Activation of Atg5-dependent placental lipophagy ameliorates cadmium-induced fetal growth restriction

Cadmium (Cd), an environmental contaminant, can result in placental non-selective autophagy activation and fetal growth restriction (FGR). However, the role of placental lipophagy, a selective autophagy, in Cd-induced FGR is unclear. This work uses case-control study, animal experiments and cultures of primary human placental trophoblast cells to explore the role of placental lipophagy in Cd-induced FGR. We found association of placental lipophagy and all-cause FGR. Meanwhile, pregnancy Cd exposure induced FGR and placental lipophgay. Inhibition of placental lipophagy by pharmacological and genetic means (Atg5^-/- mice) exacerbated Cd-caused FGR. Inversely, activating of placental lipophagy relieved Cd-stimulated FGR. Subsequently, we found that activation of Atg5-dependent lipophagy degrades lipid droplets to produce free cholesterol, and promotes placental progesterone (P4) synthesis. Gestational P4 supplementation significantly reversed Cd-induced FGR. Altogether, activation of Atg5-dependent placental lipophagy ameliorates Cd-induced FGR.

Magnetic resonance imaging presentation of diffuse and focal adenomyosis before and after pregnancy

RESEARCH QUESTION

Is there a change in magnetic resonance imaging (MRI) criteria of diffuse and focal phenotypes of adenomyosis before and after pregnancy?

DESIGN

A retrospective, monocentric, observational study in a single academic tertiary referral centre for endometriosis diagnosis and management. Women were followed for symptomatic adenomyosis, and without a prior history of surgery who give birth after 24+0 weeks. For each patient, pelvic MRI pre- and post-pregnancy was performed by two experienced radiologists with the same image acquisition protocol. Diffuse and focal adenomyosis MRI presentation were analysed before and after pregnancy.

RESULTS

Between January 2010 and September 2020, of the 139 patients analysed, 96 (69.1%) had adenomyosis at MRI distributed as follow: 22 (15.8%) presented diffuse adenomyosis, 55 (39.6%) focal adenomyosis and 19 (13.7%) both phenotypes. The frequency of isolated diffuse adenomyosis on MRI was significantly lower before versus after pregnancy (n = 22 [15.8%] versus n = 41 [29.5%], P = 0.01). The frequency of isolated focal adenomyosis was significantly higher before pregnancy than after pregnancy (n = 55 [39.6%] versus n = 34 [24.5%], P = 0.01). The mean volume of all focal adenomyosis lesions on MRI decreased significantly after pregnancy, from 6.7 ± 2.5 mm3 to 6.4 ± 2.3 mm3, P = 0.01.

CONCLUSION

The current data indicate that, based on MRI, there is an increase in diffuse adenomyosis and a decrease in focal adenomyosis after pregnancy.

The effect of obesity on uterine receptivity is mediated by endometrial extracellular vesicles that control human endometrial stromal cell decidualization and trophoblast invasion

The objectives of the present study were to determine whether obesity impacts human decidualization and the endometrial control of trophoblast invasion (both of which are required for embryo implantation) and evaluate the potential involvement of endometrial extracellular vesicles (EVs) in the regulation of these physiological processes. Using primary human cell cultures, we first demonstrated that obesity is associated with significantly lower in vitro decidualization of endometrial stromal cells (ESCs). We then showed that a trophoblastic cell line's invasive ability was greater in the presence of conditioned media from cultures of ESCs from obese women. The results of functional assays indicated that supplementation of the culture medium with EVs from nonobese women can rescue (at least in part) the defect in in vitro decidualization described in ESCs from obese women. Furthermore, exposure to endometrial EVs from obese women (vs. nonobese women) was associated with significantly greater invasive activity by HTR-8/SVneo cells. Using mass-spectrometry-based quantitative proteomics, we found that EVs isolated from uterine supernatants of biopsies from obese women (vs. nonobese women) presented a molecular signature focused on cell remodelling and angiogenesis. The proteomics analysis revealed two differentially expressed proteins (fibronectin and angiotensin-converting enzyme) that might be involved specifically in the rescue of the decidualization capacity in ESCs from obese women; both of these proteins are abundantly present in endometrial EVs from nonobese women, and both are involved in the decidualization process. In conclusion, our results provided new insights into the endometrial EVs' pivotal role in the poor uterine receptivity observed in obese women.

Fetal-maternal interactions during pregnancy: a 'three-in-one' perspective

A successful human pregnancy requires the maternal immune system to recognize and tolerate the semi-allogeneic fetus, allowing for appropriate trophoblasts invasion and protecting the fetus from invading pathogens. Therefore, maternal immunity is critical for the establishment and maintenance of pregnancy, especially at the maternal-fetal interface. Anatomically, the maternal-fetal interface has both maternally- and fetally- derived cells, including fetal originated trophoblasts and maternal derived immune cells and stromal cells. Besides, a commensal microbiota in the uterus was supposed to aid the unique immunity in pregnancy. The appropriate crosstalk between fetal derived and maternal originated cells and uterine microbiota are critical for normal pregnancy. Dysfunctional maternal-fetal interactions might be associated with the development of pregnancy complications. This review elaborates the latest knowledge on the interactions between trophoblasts and decidual immune cells, highlighting their critical roles in maternal-fetal tolerance and pregnancy development. We also characterize the role of commensal bacteria in promoting pregnancy progression. Furthermore, this review may provide new thought on future basic research and the development of clinical applications for pregnancy complications.

Parsing the Q-Markers of Baoyin Jian to Treat Abnormal Uterine Bleeding by High-Throughput Chinmedomics Strategy

Abnormal uterine bleeding (AUB) is a common and frequently occurring disease in gynecology, seriously threatening women's health. Baoyin Jian (BYJ) is a classical prescription for treating AUB. However, the lack of quality control standards of BYJ for AUB have limited the development and applications of BYJ. This experiment aims to explore the mechanism of action and screen the quality markers (Q-markers) of BYJ against AUB through the Chinmedomics strategy to improve the quality standards of Chinese medicine and provide scientific basis for its further development. BYJ has hemostatic effects in rats, as well as the ability to regulate the coagulation system following incomplete medical abortion. According to the results of histopathology, biochemical indexes and urine metabolomics, a total of 32 biomarkers of ABU in rats were identified, 16 of which can be significantly regulated by BYJ. Using traditional Chinese medicine (TCM) serum pharmacochemistry technology, 59 effective components were detected in vivo, of which 13 were highly correlated with efficacy, and 9 components, namely catalpol, rehmannioside D, paeoniflorin, berberine, phellodendrine, baicalin, asperosaponinVI, liquiritin, and glycyrrhizic acid, were screened out as the Q-markers of BYJ based on the "Five Principles" of Q-markers. In sum, BYJ can effectively alleviate abnormal bleeding symptoms and metabolic abnormalities in AUB rats. The study shows that Chinmedomics is an effective tool for screening Q-markers and provides scientific support for the further development and clinical use of BYJ.

Physiological and pathological roles of locally expressed kisspeptin and KISS1R in the endometrium

Kisspeptins, encoded by the KISS1 gene, are a family of polypeptides that bind the kisspeptin receptor (KISS1R) to perform biological functions. Produced mainly in the hypothalamus, these neuropeptides regulate the pulsatile secretion of GnRH and trigger the hypothalamus-pituitary-gonadal axis. Other peripheral organs also express kisspeptin, which inhibits metastasis. Kisspeptin and KISS1R are reportedly present in the endometrium and may play roles in limiting the migration and invasion of trophoblasts into the endometrium during pregnancy (decidua) to maintain endometrial homeostasis. A deficiency of kisspeptin and KISS1R in the endometrium can lead to pathological conditions such as endometriosis and endometrial carcinoma. Kisspeptin and KISS1R in the endometrium can also promote endometrial receptivity and decidualization. Overall, kisspeptin and KISS1R are important for maintaining the normal physiological functions of the endometrium. By summarizing the roles of kisspeptin and KISS1R in the endometrium, our review explores the regulatory roles in the peripheral reproductive system of this peptide family that plays broad and profound roles in many physiological processes.

Tissue Factor Pathway Inhibitors as Potential Targets for Understanding the Pathophysiology of Preeclampsia

BACKGROUND

Preeclampsia is a hypertensive disorder of pregnancy that causes maternal and perinatal morbidity and mortality worldwide. Preeclampsia is associated with complex abnormalities of the coagulation and fibrinolytic system. Tissue factor (TF) is involved in the hemostatic system during pregnancy, while the Tissue Factor Pathway Inhibitor (TFPI) is a major physiological inhibitor of the TF-initiated coagulation cascade. The imbalance in hemostatic mechanisms may lead to a hypercoagulable state, but prior research has not comprehensively investigated the roles of TFPI1 and TFPI2 in preeclamptic patients. In this review, we summarize our current understanding of the biological functions of TFPI1 and TFPI2 and discuss future directions in preeclampsia research.

METHODS

A literature search was performed from inception to 30 June 2022 in the PubMed and Google Scholar databases.

RESULTS

TFPI1 and TFPI2 are homologues with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 is an essential physiological inhibitor of the TF-initiated extrinsic pathway of coagulation. On the other hand, TFPI2 inhibits plasmin-mediated fibrinolysis and exerts antifibrinolytic activity. It also inhibits plasmin-mediated inactivation of clotting factors and maintains a hypercoagulable state. Furthermore, in contrast to TFPI1, TFPI2 suppresses trophoblast cell proliferation and invasion and promotes cell apoptosis. TFPI1 and TFPI2 may play important roles in regulating the coagulation and fibrinolytic system and trophoblast invasion to establish and maintain successful pregnancies. Concentrations of TF, TFPI1, and TFPI2 in maternal blood and placental tissue are significantly altered in preeclamptic women compared to normal pregnancies.

CONCLUSIONS

TFPI protein family may affect both the anticoagulant (i.e., TFPI1) and antifibrinolytic/procoagulant (i.e., TFPI2) systems. TFPI1 and TFPI2 may function as new predictive biomarkers for preeclampsia and navigate precision therapy.

Downregulation of miR-455-3p in decidual cells promotes macrophage polarization and suppresses trophoblasts invasion

Preeclampsia (PE) is a common complication of pregnancy, usually accompanied by symptoms such as hypertension and proteinuria. It can induce severe conditions that may result in maternal and fetal morbidity and fatality. In this study, we use bioinformatics analysis to compare microRNA microassay in decidual stromal cells from PE patients and healthy donors. Our result indicated that placentas from PE patients had a higher CCL1/CXCL2 expression, compared with those from healthy donors. Bioinformatics analysis confirmed that decidual stromal cells derived from PE patients expressed significantly lower miR-455-3p than those derived from healthy donors. Transfection of miR-455-3p inhibitors enhanced the CCL2/CXCL8 expression in decidual stromal cells, and luciferase activity assay confirmed that nuclear factor of activated T cells 5 (NFAT5) mRNA was the direct target of miR-455-3p; NFAT5 also promoted cytokine secretion. In the flow cytometry study, higher M1 macrophage infiltration was observed in placentas from PE patients than in those from healthy donors. We also observed that condition medium (CM) derived from decidual stromal cells could significantly promote M1 polarization of macrophages after transfection with miR-455-3p inhibitor; further, transwell invasion assay confirmed that decidual stromal cells-CM educated macrophages suppressed trophoblast invasion. Taken together, our result demonstrates that downregulation of miR-455-3p in decidual stromal cells can promote macrophage polarization and suppress trophoblasts invasion.