New insights into the mechanisms underlying recurrent pregnancy loss

TGF-β1 promoter functional gene polymorphism -509 C/T in the maternal susceptibility to recurrent pregnancy loss in South Indian women

Transforming growth factor beta 1 (TGF-β1) is an anti-inflammatory pleiotropic cytokine that regulates implantation and adhesion of trophoblasts to the extracellular matrix. It regulates the balance of Th1/Th2 cytokines and the generation of anti-inflammatory peripheral regulatory T cells (FOXP3 + Tregs), which is necessary for a healthy pregnancy. Single nucleotide polymorphisms (SNP) affecting TGF-β1 production/function may predispose to pregnancy loss. The aim of this study is to evaluate the association between the TGF-β1 -509C/T polymorphism, its serum concentrations, and recurrent pregnancy loss. The study comprised 150 RPL cases and 150 healthy controls for genotyping TGF-β1 -509C/T polymorphism using the Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR). Serum concentrations of TGF-β1 protein were estimated by enzyme-linked immunosorbent assay. From our study, women with CT genotype exhibited a protective role against RPL [OR (95 % CI) = 0.48(0.30-0.76), p = 0.002], while women with TT genotype had a significantly higher risk among RPL patients and exhibited twofold increased risk [OR (95 % CI) = 2.34(1.37-4.01), p = 0.002]. Observation of patient's follow-up data revealed a significant relation with CT genotype of unfavorable pregnancy outcome (CT vs. CC + TT, OR 2.46, 95 % C.I: 1.11-5.43, p = 0.039). Further, variant allele T was significantly elevated in women with unfavorable pregnancy compared with favorable pregnancy outcome, indicating considerable association of T allele in unfavorable pregnancy outcome (T vs. C, OR: 2.68, 95 % C.I: 1.52-4.74, p = <0.001). Serum concentrations of TGF-β1 have shown significant variation between patients and controls, as well as among RPL patients with favorable and unfavorable pregnancy outcome in correspondence to each genotype CC, CT, and TT (p < 0.05). Furthermore, genotype-dependent variation was observed within both the patient and control groups; however, this variation was not observed among RPL women with favorable and unfavorable pregnancy outcome. Our investigation revealed a significant influence of TGF-β1C-509 T polymorphism on RPL risk in South Indian women.

Alpha-lipoic acid upregulates the PPARγ/NRF2/GPX4 signal pathway to inhibit ferroptosis in the pathogenesis of unexplained recurrent pregnancy loss

Aim

With unknown etiology and limited treatment options, unexplained recurrent pregnancy loss (URPL) remains a thorny problem. Ferroptosis, a newly identified type of cell death, has been shown to be crucial in the development in reproductive disorders. This study aims to explore the specific mechanism of ferroptosis in URPL and to uncover whether alpha-lipoic acid (ALA) can inhibit ferroptosis, and then exert a protective effect in URPL.

Method

The decidua tissues of URPL and control patients who actively terminated pregnancy were collected. The CBA/J × DBA/2 murine models of URPL were established, and were randomly treated with peroxisome proliferator activated receptor γ (PPARγ) agonists (Rosiglitazone) and ALA. The CBA/J × BALB/c murine models of normal pregnancy were intraperitoneally injected with PPARγ inhibitors (T0070907). Here, we used reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH)/GSSG, and FeRhoNox-1 analysis to detect the level of ferroptosis. We used quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analysis to evaluate the mRNA level of PPARγ. Besides, western blot and immunofluorescence were utilized to test the expression profile of PPARγ/nuclear factor erythroid 2-related factor 2 (NRF2)/glutathione peroxidase 4 (GPX4).

Results

In this study, we found that iron deposition was increased in the decidual tissue of patients with URPL. Additionally, the changes in cell morphology, the level of ROS, MDA, GSH, and the expression of ferroptosis marker proteins NRF2/GPX4 confirmed activated ferroptosis in URPL. Besides, bioinformatics analysis combined with experiments confirmed that PPARγ was critical in triggering NRF2/GPX4 pathway in URPL. Furthermore, URPL mouse models were established, and the results showed that PPARγ/NRF2/GPX4-mediated ferroptosis was also significantly increased, which could be mitigated by ALA treatment.

Conclusion

Overall, these findings suggest that ferroptosis may play an important role in URPL, and ALA might be a promising therapeutic drug for improving pregnancy outcomes in URPL via targeting the PPARγ/NRF2/GPX4 pathway.

Mechanisms involved in the cytoprotective effects of Lonomia obliqua venom on human endometrial stromal cells

The pathophysiology of recurrent pregnancy loss (RPL) involves deficiencies in the proliferation and migration capacities of endometrial stromal cells (hESCs), which impair embryo implantation and development. Since animal venoms are rich source of bioactive molecules, we aimed to characterize the cytoprotective effects of Lonomia obliqua venom on hESCs. hESCs were isolated from endometrial biopsies and the mechanisms of L. obliqua venomous secretions on cell viability, proliferation and migration were characterized. Venom components were identified by chromatography and proteomic analyses. L. obliqua venom induced hESC proliferation, viability and migration in a dose-dependent manner, both in the presence and absence of serum. By ion-exchange chromatography, one fraction enriched in cytoprotective components and devoid of hemotoxins was obtained. Venom proteome identified at least six protein classes with potential cytoprotective properties (hemolins, lipocalins, hemocyannins, antiviral proteins, antimicrobial peptides, and protease inhibitors). L. obliqua venom protected hESCs from oxidative insult. Cytoprotection was also related to nitric oxide and PKC-ERK-activation and down-regulation of cAMP-PKA-dependent pathways that control cell proliferation. L. obliqua venom-induced hESC viability, proliferation and migration occurs mainly by protecting against oxidative damage and activating ERK. Thus, L. obliqua venom components are promising pharmacological tools to understand the underlying mechanisms of hESC deficiency in RPL.

Association of Y chromosome AZF region microdeletions with recurrent miscarriage in Iranian couples: A case-control study

BACKGROUND

Recent studies have linked recurrent pregnancy loss (RPL) to abnormalities in the sperm genome, specifically microdeletions in the azoospermia factor (AZF) region. This study investigated the potential association between Y chromosome microdeletions in the AZF region and RPL in Iranian couples.

METHODS

The research presents a case-control study of 240 men: 120 whose partners experienced recurrent miscarriage, and 120 who had successful pregnancies without history of miscarriage. The study used semen parameters, hormone analyses, and microdeletion analysis via multiplex PCR and the YChromStrip kit. Thus, the sequence-tagged site (STS) markers of AZFa (sY84, sY86), AZFb (sY127, sY134), and AZFc (sY254, sY255) regions were examined.

RESULTS

The variations in semen parameters and sex hormone levels between cases and controls are suggest impaired testicular function in men whose partners had recurrent miscarriages (p < 0.05). Furthermore, the study revealed a negative correlation between sperm count and follicle-stimulating hormone (FSH) level, and a positive one between sperm motility and testosterone concentration. There were no microdeletions in the control group, while the RPL group showed 20 deletions in AZFb (sY134) (16.66%) and 10 deletions each in AZFb (sY127) (8.33%) and AZFc (sY254) (8.33%).

CONCLUSION

Microdeletions in sY134 (AZFb) were significantly associated with RPL in Iranian men (p = 0.03). AZF microdeletion screening in couples with RPL can provide valuable information for ethnical genetic counseling and management of recurrent miscarriage. Further studies on larger populations or across various ethnic groups, conclusions and the inclusion of other factors like epigenetic changes explain the role of AZF microdeletions in RPL.

Skp2: A critical molecule for ubiquitination and its role in cancer

The ubiquitin-proteasome system (UPS) is a multi-step process that serves as the primary pathway for protein degradation within cells. UPS activity also plays a crucial role in regulating various life processes, including the cell cycle, signal transduction, DNA repair, and others. The F-box protein Skp2, a crucial member of the UPS, plays a central role in the development of various diseases. Skp2 controls cancer cell growth and drug resistance by ubiquitinating modifications to a variety of proteins. This review emphasizes the multifaceted role of Skp2 in a wide range of cancers and the mechanisms involved, highlighting the potential of Skp2 as a therapeutic target in cancer. Additionally, we describe the impactful influence exerted by Skp2 in various other diseases beyond cancer.

Gene-network based analysis of human placental trophoblast subtypes identifies critical genes as potential targets of therapeutic drugs

During early pregnancy, extravillous trophoblasts (EVTs) play a crucial role in modifying the maternal uterine environment. Failures in EVT lineage formation and differentiation can lead to pregnancy complications such as preeclampsia, fetal growth restriction, and pregnancy loss. Despite recent advances, our knowledge on molecular and external factors that control and affect EVT development remains incomplete. Using trophoblast organoid in vitro models, we recently discovered that coordinated manipulation of the transforming growth factor beta (TGFβ) signaling is essential for EVT development. To further investigate gene networks involved in EVT function and development, we performed weighted gene co-expression network analysis (WGCNA) on our RNA-Seq data. We identified 10 modules with a median module membership of over 0.8 and sizes ranging from 1005 (M1) to 72 (M27) network genes associated with TGFβ activation status or in vitro culturing, the latter being indicative for yet undiscovered factors that shape the EVT phenotypes. Lastly, we hypothesized that certain therapeutic drugs might unintentionally interfere with placentation by affecting EVT-specific gene expression. We used the STRING database to map correlations and the Drug-Gene Interaction database to identify drug targets. Our comprehensive dataset of drug-gene interactions provides insights into potential risks associated with certain drugs in early gestation.

The number of prior pregnancy losses does not impact euploidy rates in young patients with idiopathic recurrent pregnancy loss

PURPOSE

Our study aimed to determine the possible factors that might impact the probability of obtaining a euploid blastocyst following intracytoplasmic sperm injection (ICSI) and preimplantation genetic testing for aneuploidy (PGT-A) procedures in idiopathic recurrent pregnancy loss (RPL) patients.

METHODS

This single-center retrospective cohort analysis included 180 oocyte retrieval cycles of 166 women under 35 years old and those diagnosed with idiopathic RPL according to American Society of Reproductive Medicine (ASRM) guidelines. Trophectoderm biopsy and next-generation sequencing (NGS) were the techniques used. Patients were stratified by the number of previous losses (Group A: 2, Group B: 3, and Group C: > 3).

RESULTS

Baseline and embryological characteristics showed no statistically significant differences. The euploidy rate per analyzed blastocyst was comparable within the groups (63.3%, 58.2%, and 58.5%; p = 0.477). Logistic regression analyses confirmed that only the trophectoderm scores of A and B increased the probability of obtaining a euploid embryo [OR: 1.82, 95% CI (1.120-2.956), p: 0.016].

CONCLUSION

It is concluded that there was no correlation between the number of previous losses and the chance of finding at least one euploid embryo in ICSI cycles of women younger than 35 years.

The Relationship of Preconception and Early Pregnancy Isoprostanes with Fecundability and Pregnancy Loss

BACKGROUND

Although redox stress likely plays an important role in reproductive health, the utility of peripheral biomarkers of oxidative stress, such as isoprostanes, during the periconception period remains underexplored. We evaluated the relationship between isoprostanes during preconception and gestational week 4 and women's reproductive health outcomes.

METHODS

The Effects of Aspirin in Gestation and Reproduction trial (2007-2011) enrolled 1228 women attempting pregnancy and followed them for up to 6 menstrual cycles and throughout pregnancy if they became pregnant. We measured creatinine-adjusted, log-transformed isoprostanes 8-iso-prostaglandin F 2α (8-iso-PGF2α), its metabolite 2,3-dinor-iPF2α-III, and stereoisomers 5-iso-PGF2α-VI and 8,12-iso-iPF2α-VI in urine during preconception and 4 weeks gestation. We evaluated pregnancy among participants in each menstrual cycle using human chorionic gonadotropin (hCG) and defined pregnancy loss as observed loss following positive hCG. We calculated fecundability odds ratios (FOR) and 95% confidence intervals (CI) using discrete-time Cox proportional hazards models and relative risk of pregnancy loss using adjusted log-binomial models.

RESULTS

Higher preconception isoprostane levels were associated with lower fecundability [e.g., FOR = 0.89; 95% CI = 0.81, 0.97 per interquartile range (IQR) increase in 8-iso-PGF2α]. Among 797 pregnancies, isoprostane levels increased from preconception to 4 weeks gestation (e.g., mean difference = 0.12; 95% CI = 0.10, 0.14 ng/mL for 8-iso-PGF2α) and higher isoprostanes at 4 weeks gestation were associated with lower risk of pregnancy loss (e.g., RR = 0.79; 95% CI = 0.62, 1.00 per IQR increase in 8-iso-PGF2α).

CONCLUSIONS

Preconception urinary isoprostanes may identify redox stress pathways associated with lower fecundability. However, the increase in isoprostanes into gestational week 4 and the associated lower risk of pregnancy loss may suggest confounding by latent factors in early pregnancy.

Decreased expression and DNA hypermethylation of syncytin-1 in human villus tissues with unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) affects approximately 5 % of women of reproductive age worldwide. The etiology and pathogenesis of approximately 50 % of RSA cases currently remain unclear, which known as unexplained RSA (URSA). Syncytin-1, an envelope protein encoded by HERV-W gene, is essential for human embryonic development. The purpose of this study was to explore the correlation between syncytin-1 expression and URSA occurrence. The villi tissues of URSA patients and patients with voluntary termination of pregnancy for non-medical reasons in early pregnancy (Control group) were collected. Compared with the Control group, syncytin-1 was abnormally low expressed in URSA villus tissues, and the HERV-W gene promoter was hypermethylated. Compared with the control group, the global DNA methylation level and the expression level of DNA methylases in the villus tissues of the URSA group had no significant difference. In addition, compared with the Control group, URSA villus tissue showed obviously abnormal apoptosis. Overexpression of syncytin-1 promoted the proliferation of HTR-8 cells and inhibited their apoptosis; while knockdown of syncytin-1 inhibited cell proliferation and promoted cell apoptosis. URSA villus tissue exhibited hypermethylation of the HERV-W gene and down-regulation of syncytin-1 expression. Syncytin-1 has the potential to be a predictive and diagnostic biomarker for URSA.

Impact of recurrent pregnancy loss history on reproductive outcomes in women undergoing fertility treatment

BACKGROUND

Recurrent pregnancy loss negatively affects the reproductive outcomes of natural conception. Preimplantation genetic testing for aneuploidies has been the focus of interventions in women with recurrent pregnancy loss. However, the risk of no embryos being available, high costs, and uncertainties surrounding its effectiveness limit its use. Factors beyond euploidy, such as an appropriate intrauterine environment, are also important for improving the reproductive outcomes in women with recurrent pregnancy loss. It remains unknown whether a history of recurrent pregnancy loss can affect reproductive outcomes after fertility treatment.

OBJECTIVE

This study aimed to investigate the impact of history of recurrent pregnancy loss on the reproductive outcomes of women undergoing fertility treatment.

STUDY DESIGN

This was a retrospective cohort study of women who underwent their first frozen embryo transfer cycle or intrauterine insemination cycle between January 2014 and July 2020 in Shanghai, China. We excluded couples with known karyotypic abnormalities (eg, balanced translocation) or uterine malformation. We performed multivariate binary logistic regressions for biochemical pregnancy, miscarriage, and live birth rates to investigate the associations between recurrent pregnancy loss history and reproductive outcomes.

RESULTS

A total of 29,825 women who underwent frozen embryo transfer cycles and 5476 women who underwent intrauterine insemination cycles were included in this study. In those who underwent frozen embryo transfer, history of recurrent pregnancy loss was not significantly associated with biochemical pregnancy (adjusted odds ratio, 1.19; 95% confidence interval, 0.87-1.63), miscarriage (adjusted odds ratio, 0.99; 95% confidence interval, 0.78-1.26), or live birth rates (adjusted odds ratio, 0.91; 95% confidence interval, 0.79-1.06). Similarly, in frozen embryo transfer cycles that led to clinical pregnancy, recurrent pregnancy loss history was not significantly associated with live birth (adjusted odds ratio, 0.99; 95% confidence interval, 0.76-1.28) or miscarriage rates (adjusted odds ratio, 1.04; 95% confidence interval, 0.81-1.35). In women with intrauterine insemination, history of recurrent pregnancy loss showed no significant associations with fertility outcomes in all cycles ([adjusted odds ratio, 1.36; 95% confidence interval, 0.88-2.10] for live birth rate and [adjusted odds ratio, 1.74; 95% confidence interval, 0.75-4.01], for miscarriage rate) and in cycles that led to clinical pregnancy ([adjusted odds ratio, 0.70; 95% confidence interval, 0.31-1.63] for live birth rate and [adjusted odds ratio, 1.45; 95% confidence interval, 0.58-3.63] for miscarriage rate).

CONCLUSION

In women without obvious chromosome abnormality and uterine malformation who undergo fertility treatment, recurrent pregnancy loss history was not significantly associated with miscarriage and live birth rates, suggesting that it has little or no prognostic value in predicting the reproductive outcomes of frozen embryo transfer or intrauterine insemination cycles.

The Update Immune-Regulatory Role of Pro- and Anti-Inflammatory Cytokines in Recurrent Pregnancy Losses

Recurrent pregnancy losses (RPL) is a common reproductive disorder with various underlying etiologies. In recent years, rapid progress has been made in exploring the immunological mechanisms for RPL. A propensity toward Th2 over Th1 and regulatory T (Treg) over Th17 immune responses may be advantageous for reproductive success. In women with RPL and animals prone to abortion, an inordinate expression of cytokines associated with implantation and early embryo development is present in the endometrium or decidua secreted from immune and non-immune cells. Hence, an adverse cytokine milieu at the maternal-fetal interface assaults immunological tolerance, leading to fetal rejection. Similar to T cells, NK cells can be categorized based on the characteristics of cytokines they secrete. Decidual NK (dNK) cells of RPL patients exhibited an increased NK1/NK2 ratio (IFN-γ/IL-4 producing NK cell ratios), leading to pro-inflammatory cytokine milieu and increased NK cell cytotoxicity. Genetic polymorphism may be the underlying etiologies for Th1 and Th17 propensity since it alters cytokine production. In addition, various hormones participate in cytokine regulations, including progesterone and estrogen, controlling cytokine balance in favor of the Th2 type. Consequently, the intricate regulation of cytokines and hormones may prevent the RPL of immune etiologies. Local or systemic administration of cytokines or their antagonists might help maintain adequate cytokine milieu, favoring Th2 over Th1 response or Treg over Th17 immune response in women with RPL. Herein, we provided an updated comprehensive review regarding the immune-regulatory role of pro- and anti-inflammatory cytokines in RPL. Understanding the roles of cytokines involved in RPL might significantly advance the early diagnosis, monitoring, and treatment of RPL.

Autophagy markers are dysregulated in the endometrial tissues of patients with unexplained repeated implantation failure

Endometrium decidualization is a complex biological process, which includes the interplay of transcription factors, cytokines, cell cycle regulators, and other signaling pathways. However, the underlying molecular mechanisms of this process are not fully elucidated to date. In this study, we aimed to investigate the possible association between autophagy and recurrent implantation failure (RIF). A total of 81 genes were downregulated and 231 genes were upregulated in the RIF group compared with the control group, and the differences were statistically significant (p < 0.05). Further, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were analyzed, and we found that some autophagy markers, for example, LC3-II, LAMP2, and HIF-1α were significantly increased, whereas P62 was drastically downregulated in the RIF group. Similar results were observed in proteins level; and the autophagy puncta were also markedly enhanced in the endometrial tissues of RIF patients. Autophagy is closely associated with the RIF occurs and may be involved in the pathogenesis of RIF.

Decidualization of human endometrial stromal cells requires steroid receptor coactivator-3

Steroid receptor coactivator-3 (SRC-3; also known as NCOA3 or AIB1) is a member of the multifunctional p160/SRC family of coactivators, which also includes SRC-1 and SRC-2. Clinical and cell-based studies as well as investigations on mice have demonstrated pivotal roles for each SRC in numerous physiological and pathophysiological contexts, underscoring their functional pleiotropy. We previously demonstrated the critical involvement of SRC-2 in murine embryo implantation as well as in human endometrial stromal cell (HESC) decidualization, a cellular transformation process required for trophoblast invasion and ultimately placentation. We show here that, like SRC-2, SRC-3 is expressed in the epithelial and stromal cellular compartments of the human endometrium during the proliferative and secretory phase of the menstrual cycle as well as in cultured HESCs. We also found that SRC-3 depletion in cultured HESCs results in a significant attenuation in the induction of a wide-range of established biomarkers of decidualization, despite exposure of these cells to a deciduogenic stimulus and normal progesterone receptor expression. These molecular findings are supported at the cellular level by the inability of HESCs to morphologically transform from a stromal fibroblastoid cell to an epithelioid decidual cell when endogenous SRC-3 levels are markedly reduced. To identify genes, signaling pathways and networks that are controlled by SRC-3 and potentially important for hormone-dependent decidualization, we performed RNA-sequencing on HESCs in which SRC-3 levels were significantly reduced at the time of administering the deciduogenic stimulus. Comparing HESC controls with HESCs deficient in SRC-3, gene enrichment analysis of the differentially expressed gene set revealed an overrepresentation of genes involved in chromatin remodeling, cell proliferation/motility, and programmed cell death. These predictive bioanalytic results were confirmed by the demonstration that SRC-3 is required for the expansion, migratory and invasive activities of the HESC population, cellular properties that are required in vivo in the formation or functioning of the decidua. Collectively, our results support SRC-3 as an important coregulator in HESC decidualization. Since perturbation of normal homeostatic levels of SRC-3 is linked with common gynecological disorders diagnosed in reproductive age women, this endometrial coregulator-along with its new molecular targets described here-may open novel clinical avenues in the diagnosis and/or treatment of a non-receptive endometrium, particularly in patients presenting non-aneuploid early pregnancy loss.

Maternal selection of human embryos in early gestation: Insights from recurrent miscarriage

Compared to most mammals, human pregnancy is unusual in that it involves chromosomally diverse embryos, cyclical breakdown and regeneration of the uterine mucosa, and intimate integration of fetal and maternal cells at the uteroplacental interface. Not surprisingly, pregnancy often falters in early gestation. Whether these losses result in clinical miscarriages depends on the origins and impacts of chromosomal errors on fetal development and the ability of the decidualizing endometrium to engage in embryo biosensing and selection. Aneuploidy originating in oocytes during meiosis drives the age-related risk of miscarriage. By contrast, the frequency of endometrial cycles with an impaired decidual response may account for the stepwise increase in miscarriage rates with each pregnancy loss independently of maternal age. Additional physiological mechanisms operate in early gestation to ensure that most failing pregnancies are lost before vascular maternal-fetal connections are established by the end of the first trimester. Here, we summarise how investigations into the mechanisms that cause miscarriage led to new insights into the processes that govern maternal selection of human embryos in early gestation.

Patients with Recurrent Pregnancy Loss Have Similar Embryonic Preimplantation Genetic Testing Aneuploidy Rates and In Vitro Fertilization Outcomes to Infertility Patients

Objective

To evaluate aneuploidy rates and in vitro fertilization (IVF)/pregnancy outcomes for patients undergoing IVF and preimplantation genetic testing for aneuploidy (PGT-A) with a recurrent pregnancy loss (RPL) diagnosis compared to infertility diagnoses without RPL.

Design

Retrospective cohort study.

Setting

Academic fertility center.

Patients

Of 372 patients undergoing IVF/PGT-A between January 2016-December 2018, 294 patients were included in the analysis: 56 patients with an RPL diagnosis and 238 with infertility diagnoses without RPL.

Interventions

None.

Main Outcome Measures

The primary outcome measured was the embryonic aneuploidy rate. Secondary outcomes included fertilization and blastulation rates, number of blastocysts biopsied, cycles without euploid blastocysts, and rates of pregnancy losses, clinical pregnancies, and live births after a euploid embryo transfer.

Results

The cohort included 56 patients with RPL and 238 patients without RPL, including data from their first IVF cycle within the time period. Aneuploidy rates were similar between the groups, with a mean of 55% (±31%) in RPL and 54% (±34%) in non-RPL cycles. Similar rates persisted after controlling for age, ovarian reserve, and infertility diagnosis. Fertilization and blastulation rates, as well as cumulative clinical pregnancy, pregnancy loss, and live birth rates after the transfer of at least one euploid embryo were also similar between the two groups.

Conclusions

These results suggest that IVF/PGT-A cycles from patients with an RPL diagnosis have similar IVF and pregnancy outcomes to those of patients with infertility without RPL. This research can help guide counseling for RPL patients considering IVF with PGT-A.

TMT-Based Proteomic Analysis of Human Spermatozoa from Unexplained Recurrent Miscarriage Patients before and after Oral Antioxidant Treatment

Recently, sperm quality and the presence of double-stranded breaks (DSB) has been pointed out as a possible cause of recurrent miscarriage, and the use of antioxidants has expanded as a treatment for male infertility. The aim of the present study was to analyze the proteomic effects of antioxidants on sperm from RM patients with high incidence of DSB. Proteomic analysis was performed using a tandem mass tag labeling technique, and subsequently compared with the PANTHER database for DEPs, and the STRING database for protein–protein interactions (PPI). Differentially expressed proteins (DEPs) both before and after antioxidant oral treatment were identified. PPI involving DEPs clustered into networks related to cell metabolism, cytoskeleton, and DNA damage. Results show that the sperm proteomic profiles before and after antioxidant treatment do not significantly differ from each other. However, some DEPs found after the antioxidant treatment shifted towards a DEPs profile typical of fertile donors. This indirect measurement suggests an improvement caused by antioxidants on the expression of several proteins. Among them were proteins involved in sperm DNA remodeling (LMO7, MMP28, BNC2, H2B, and PRDM2). The results presented here represent the first approach in the analysis and repair of the proteomic change caused by antioxidants in recurrent miscarriage patients, elucidating biomarkers that may be useful for the diagnosis and further sperm selection in this type of patient. Further studies should be conducted to validate the usefulness of these biomarkers in larger study groups.

Diagnosis and management of idiopathic recurrent pregnancy loss (RPL): Current immune testing and immunomodulatory treatment practice in the United Kingdom

Recurrent pregnancy loss (RPL) affects 1.9 % of couples. Despite the severe physical, psychological, and economic impact of RPL, miscarriage care provision remains highly heterogeneous. Due to the absence of strong scientific evidence, national and international guidelines on the diagnosis and treatment of this condition remain unclear and often contradictory. In the absence of identifiable RPL-associated risk factors, when the condition is termed "idiopathic", immunological tests and immunomodulatory treatments are sometimes suggested even though the contribution of aberrant immune activity to this condition remains undetermined. Through an online survey, distributed across the UK (37.7% response rate), a high variation in clinical practice was detected, with multiple RPL definitions utilized and different tests employed for potential risk factor identification. Immunological testing was found to be provided in 7.9 %(N = 3) of the included clinics. Moreover, multiple therapies, including immunomodulatory ones were utilized for the management of idiopathic RPL. These findings highlight a need for additional research on the implication of immune activity in this condition. The high variation between clinics regarding the tests employed for the diagnosis and management of idiopathic RPL also underlines the need for guidelines to direct clinical practice, taking into consideration both the patients' needs but also the strength of the available scientific evidence.

An Altered Microbiota in the Lower and Upper Female Reproductive Tract of Women with Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is a complex multifactorial disease. Recently, the microbiota of the female reproductive tract, as an emerging factor in RSA, has gradually attracted the attention of many clinical researchers. Here, we reported that the microbiota of the lower and upper female reproductive tracts from patients with RSA showed no significant differences in alpha diversity compared to that of controls. Beta diversity was significantly higher in the RSA group than in the control group in the vaginal microbiota (P = 0.036), cervical microbiota (P = 0.010) and microbiota from uterine lavage fluid (P = 0.001). In addition, dramatic decreases in gamma interferon and interleukin-6 cytokine levels were observed in the RSA group. In conclusion, our data suggested altered microbial biodiversity in the vagina, cervix and uterine lavage fluid in the RSA group. Alterations in the microbiota in the uterine cavity could be associated with altered cytokine levels, which might be a risk factor for RSA pathogenesis. Moreover, the microbiota composition differed markedly from the lower genital tract to the uterine cavity, and the microbiota in the uterine cavity also distinctly varied between endometrial tissue and uterine lavage fluid in the RSA group. Hence, sampling with these two methods simultaneously allowed a more comprehensive perspective of microbial colonization in the uterine cavity. IMPORTANCE As an obstacle to pregnancy, recurrent spontaneous abortion (RSA) can be caused by a variety of factors, and a current understanding of the etiology of RSA is still lacking; half of cases have an unknown cause. A substantial fraction of patients show no improvement after treatment. Since the microbiota of the female reproductive tract has been proposed as an emerging factor in RSA patients, further investigation is needed to provide guidance for clinical therapy. In general, this is the first report describing the distinct alterations of the vaginal, cervical, and uterine microbiota in RSA, not just that in the vagina. Furthermore, another major strength of this study derived from the further in-depth investigation and analysis of the characteristics of the microbiota colonizing the upper female genital tract in RSA, which provided a more comprehensive view for investigating the uterine microbiota.

Expression and function of the luteinizing hormone choriogonadotropin receptor in human endometrial stromal cells

The human luteinising hormone choriogonadotropin receptor (LHCGR) is a G-protein coupled receptor activated by both human chorionic gonadotropin (hCG) and luteinizing hormone (LH), two structurally related gonadotropins with essential roles in ovulation and maintenance of the corpus luteum. LHCGR expression predominates in ovarian tissues where it elicits functional responses through cyclic adenosine mononucleotide (cAMP), Ca²⁺ and extracellular signal-regulated kinase (ERK) signalling. LHCGR expression has also been localized to the human endometrium, with purported roles in decidualization and implantation. However, these observations are contentious. In this investigation, transcripts encoding LHCGR were undetectable in bulk RNA sequencing datasets from whole cycling endometrial tissue and cultured human endometrial stromal cells (EnSC). However, analysis of single-cell RNA sequencing data revealed cell-to-cell transcriptional heterogeneity, and we identified a small subpopulation of stromal cells with detectable LHCGR transcripts. In HEK-293 cells expressing recombinant LHCGR, both hCG and LH elicited robust cAMP, Ca²⁺ and ERK signals that were absent in wild-type HEK-293 cells. However, none of these responses were recapitulated in primary EnSC cultures. In addition, proliferation, viability and decidual transformation of EnSC were refractory to both hCG and LH, irrespective of treatment to induce differentiation. Although we challenge the assertion that LHCGR is expressed at a functionally active level in the human endometrium, the discovery of a discrete subpopulation of EnSC that express LHCGR transcripts may plausibly account for the conflicting evidence in the literature.

A Potential Mechanism of Kidney-Tonifying Herbs Treating Unexplained Recurrent Spontaneous Abortion: Clinical Evidence From the Homogeneity of Embryo Implantation and Tumor Invasion

Background: Kidney-tonifying herbs (KTHs) are widely used to treat unexplained recurrent spontaneous abortion (URSA) based on the theory of traditional Chinese medicine (TCM). However, there is still a lack of systematic evaluation and mechanistic explanation for these treatments.

Objective: The purpose of this study was to assess the clinical efficacy, and to investigate the potential mechanisms, of KTH based on TCM for the treatment of URSA.

Methods: A systematic literature search was conducted within PubMed, Embase, China Biomedical Literature database, Web of Science (WOS), China National Knowledge Infrastructure (CNKI) database, and the Wanfang database to find articles reporting on the Chinese herbal formula based around KTH for treating URSA, which were published between January 2010 and June 2021. A full bibliometric analysis was carried out; in addition, randomized controlled trial (RCT) articles were selected for systematic evaluation and meta-analysis. The drugs with the highest frequency of KTHs were screened for meta-analysis. Finally, network analysis and molecular docking were used to study the key components and potential pathway of KTHs in the treatment of URSA.

Results: The meta-analysis included nine RCTs involving 1,054 subjects. Compared with the control groups, the clinical efficacy of TCM-based KTHs in the treatment of URSA patients significantly improved outcomes. Additionally, a component target pathway network was identified, which included 32 potential blood activating components and 113 main targets. Japonine, sopranol, lysine, and matrine were considered the most important bioactive molecules for KTHs. The key potential therapeutic pathway for URSA was a tumor-related signaling pathway. The target genes for URSA regulated by KTHs were highly similar to tumor biological processes such as the regulation of apoptotic signaling pathways, inflammatory responses, angiogenesis, and epithelial metabolic transition.

Conclusion: KTH has great potential for treating URSA. Because the maintenance of pregnancy has a high similarity with tumor invasion, the research relating to tumor mechanisms should also be followed up as it may lead to new ideas and breakthroughs for research into URSA. At the same time, embryonic and decidual cells share a high degree of cellular heterogeneity and spatial structural complexity with tumor cells, and a single cell combined with spatial omics may be the best future approach for validating KTH mechanisms.

Understanding human immunity in idiopathic recurrent pregnancy loss

Miscarriage, defined as the loss of a pregnancy before a viable gestation, affects 1 in 6 couples. Recurrent pregnancy loss (RPL), defined as two or more miscarriages, affects up to 1.9% of couples. The physical, psychological, and financial impact of miscarriage can be substantial. However, despite its multifactorial etiology, for up to 50% of couples a reason behind this condition cannot be identified, termed 'idiopathic RPL'. Much recent research has strived to understand this, with immune dysregulation being a source of particular interest. In this short review we summarize the current evidence on the complex role of the immune system both pre- and early post-conception in RPL. A key question is whether systemic peripheral blood markers, in particular natural killer cell and T cells, may be utilized to accurately predict and/ or diagnose those pregnancies at high risk of loss. Given the invasive nature of endometrial testing, identification of reliable peripheral immune biomarkers is particularly appealing. Clinical trials using potent immunomodulatory agents, including intravenous immunoglobulin, donor leukocyte immunization, and tumor necrosis factor (TNF)-α inhibitors, have been undertaken with the primary objective of preventing miscarriage in women with RPL. Standardisation of both diagnostic and prognostic immune cell testing assays is required to permit accurate identification of those women who may benefit from immunomodulation. Prompt clarification is required to meet the increasing expectation from couples and clinicians, as without these advancements women are at risk of exposure to potent immune-therapies and subsequent studies are at risk of failure, generating further controversy regarding the role of immune dysregulation in women with RPL. Through this review we highlight clear gaps in our current knowledge on immune activity in RPL.

The Role of Decidual Subpopulations in Implantation, Menstruation and Miscarriage

In each menstrual cycle, the endometrium becomes receptive to embryo implantation while preparing for tissue breakdown and repair. Both pregnancy and menstruation are dependent on spontaneous decidualization of endometrial stromal cells, a progesterone-dependent process that follows rapid, oestrogen-dependent proliferation. During the implantation window, stromal cells mount an acute stress response, which leads to the emergence of functionally distinct decidual subsets, reflecting the level of replication stress incurred during the preceding proliferative phase. Progesterone-dependent, anti-inflammatory decidual cells (DeC) form a robust matrix that accommodates the conceptus whereas pro-inflammatory, progesterone-resistant stressed and senescent decidual cells (senDeC) control tissue remodelling and breakdown. To execute these functions, each decidual subset engages innate immune cells: DeC partner with uterine natural killer (uNK) cells to eliminate senDeC, while senDeC co-opt neutrophils and macrophages to assist with tissue breakdown and repair. Thus, successful transformation of cycling endometrium into the decidua of pregnancy not only requires continuous progesterone signalling but dominance of DeC over senDeC, aided by recruitment and differentiation of circulating NK cells and bone marrow-derived decidual progenitors. We discuss how the frequency of cycles resulting in imbalanced decidual subpopulations may determine the recurrence risk of miscarriage and highlight emerging therapeutic strategies.

A meta-analysis for association of eNOS VNTR 4b/a, - 786 T > C and + 894G > T polymorphisms with risk of recurrent pregnancy loss

BACKGROUND

The association of polymorphisms at nitric oxide synthases (eNOS) gene with recurrent pregnancy loss (RPL) susceptibility has been the focus of attention in several studies. However, the conclusions have been divergent and controversial. Therefore, we performed this study to precisely evaluate the association of eNOS polymorphisms with the risk of RPL.

METHODS

A universal search in PubMed, Web of Knowledge, SciELO, MedRxiv, Scopus and web of Science was performed to identify relevant studies up to January 25, 2020.

RESULTS

A total of 39 eligible studies including 15 studies with 2274 cases and 1933 controls on VNTR 4b/a, nine studies with 1640 cases and 1268 controls on -786C > T, and 15 studies with 2660 cases and 2557 controls on + 894G > T polymorphism were selected. Pooled data revealed that eNOS VNTR 4b/a (dominant model: OR = 1.174, 95% CI 1.021-1.350, p = 0.025) and + 894G > T (allele model: OR = 1.278, 95% CI 1.024-1.595, p = 0.030; homozygote model: OR = 1.442, 95% CI 1.084-1.917, p = 0.012; dominant model: OR = 1.305, 95% CI 1.006-1.693, p = 0.045; and recessive model: OR = 1.378, 95% CI 1.045-1.817, p = 0.023) polymorphisms were significantly associated with an increased risk of RPL, but not  - 786 T > C. Stratified analysis by ethnicity revealed that the eNOS + 894G > T was associated with RPL risk in Asians.

CONCLUSIONS

To sum up, our results indicated that the eNOS VNTR 4b/a and + 894G > T polymorphisms might be contributing to RPL development, but not the  - 786C > T polymorphism.

Embryo biosensing by uterine natural killer cells determines endometrial fate decisions at implantation

Decidualizing endometrial stromal cells (EnSC) critically determine the maternal response to an implanting conceptus, triggering either menstruation-like disposal of low-fitness embryos or creating an environment that promotes further development. However, the mechanism that couples maternal recognition of low-quality embryos to tissue breakdown remains poorly understood. Recently, we demonstrated that successful transition of the cycling endometrium to a pregnancy state requires selective elimination of pro-inflammatory senescent decidual cells by activated uterine natural killer (uNK) cells. Here we report that uNK cells express CD44, the canonical hyaluronan (HA) receptor, and demonstrate that high molecular weight HA (HMWHA) inhibits uNK cell-mediated killing of senescent decidual cells. In contrast, low molecular weight HA (LMWHA) did not attenuate uNK cell activity in co-culture experiments. Killing of senescent decidual cells by uNK cells was also inhibited upon exposure to medium conditioned by IVF embryos that failed to implant, but not successful embryos. Embryo-mediated inhibition of uNK cell activity was reversed by recombinant hyaluronidase 2 (HYAL2), which hydrolyses HMWHA. We further report a correlation between the levels of HYAL2 secretion by human blastocysts, morphological scores, and implantation potential. Taken together, the data suggest a pivotal role for uNK cells in embryo biosensing and endometrial fate decisions at implantation.

The long noncoding RNA MEG3 regulates Ras-MAPK pathway through RASA1 in trophoblast and is associated with unexplained recurrent spontaneous abortion

Background

Maternally Expressed Gene 3 (MEG3) is expressed at low levels in placental villi during preeclampsia; however, its roles in unexplained recurrent spontaneous abortion (URSA) remain unclear. In this study, we aimed to explore the relationship between MEG3 and URSA.

Methods

The differentially expressed lncRNAs (MEG3) and its downstream genes (RASA1) were identified using bioinformatics analysis of Genomic Spatial Event (GSE) database. The expression levels of MEG3 in embryonic villis (with gestational ages of 49–63 days) and primary trophoblasts were determined using quantitative RT-PCR assay. A mouse model of Embryo implantation, Cell Counting Kit-8 (CCK-8), flow cytometry, and Transwell migration assays were performed to determine the implantation, proliferative, apoptotic, and invasive capacities of trophoblast. The level of phosphorylated core proteins in the RAS-MAPK pathway were analyzed using Western blot assay. The mechanisms of MEG3 in the regulation of RASA1 were studied by RNA pulldown, RNA immunoprecipitation (RIP), DNA pulldown, and chromatin immunoprecipitation (ChIP) assays.

Results

MEG3 had a low expression level in embryonic villis of 102 URSA patients compared with those of 102 normal pregnant women. MEG3 could promote proliferation and invasion, inhibit the apoptosis of primary trophoblast of URSA patients (PT-U cells), as well as promote embryo implantation of mouse. Besides, MEG3 also promoted the phosphorylation of rapidly accelerated fibrosarcoma (Raf), mitogen-activated protein kinase kinase (MEK), and extracellular-signal-regulated kinase (ERK) proteins. The results of RNA pull down and RIP assays showed that MEG3 bound with the enhancer of zeste homolog 2 (EZH2). The DNA pulldown assay revealed that MEG3 could bind to the promoter sequence of the RAS P21 Protein Activator 1 (RASA1) gene. Further, the ChIP assay showed that MEG3 promoted the binding of EZH2 to the promoter region of the RASA1 gene.

Conclusions

The inactivation of MEG3 in embryonic villi association with URSA; MEG3 inhibited the expression of RASA1 by mediating the histone methylation of the promoter of RASA1 gene by EZH2, thereby activating the RAS-MAPK pathway and enhancing the proliferative and invasive capacities of trophoblasts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00337-9.

Abnormal H3K27 histone methylation of RASA1 gene leads to unexplained recurrent spontaneous abortion by regulating Ras-MAPK pathway in trophoblast cells

Some studies suggest that the inactivation of the Ras-MAPK pathway in trophoblast cells can lead to recurrent abortion, but the molecular mechanism underlying the inactivation of this pathway in trophoblast cells is still unclear. This study aimed to explore the relationship between the mechanism of abnormal activation of RASA1, a regulatory protein of the Ras-MAPK pathway, and unexplained recurrent spontaneous abortion. RT-qPCR was used to detect the transcription levels of RASA1 gene. Immunohistochemistry and Western blot were used to detect the expression levels of the RASA1, Raf and MEK proteins. CCK-8, TUNEL and Transwell assays were used to detect the proliferative, apoptotic, and invasive capacities of HTR-8/SVneo cells. ChIP assays were used to detect the enrichment of H3K27me3 in RASA1 gene promoter. Abortion villi experiments showed that the enrichment of H3K27me3 in the RASA1 gene promoter was reduced, and that both RASA1 gene transcription and RASA1 protein expression were increased. Cell experiments confirmed that RASA1 could decrease the phosphorylated Raf and MEK proteins, inhibit the proliferation and invasion ability, and promote the apoptosis ability of HTR-8/SVneo cells. It was also found that the proliferation and invasion ability as well as the Ras-MAPK pathway activity of HTR-8/SVneo cells were inhibited when treated with histone methyltransferase inhibitor DZNep. RASA1 gene was abnormally activated in unexplained recurrent spontaneous abortion villi due to the decreased enrichment of H3K27me3 in the gene promoter. High expression of RASA1 could inhibit the activity of the Ras-MAPK pathway, and thus inhibit the proliferation and invasion ability of trophoblast cells.

Downregulation of decidual SKP2 is associated with human recurrent miscarriage

BACKGROUND

Recurrent miscarriage (RM) is a very frustrating problem for both couples and clinicians. To date, the etiology of RM remains poorly understood. Decidualization plays a critical role in implantation and the maintenance of pregnancy, and its deficiency is closely correlated with RM. The F-box protein S-phase kinase associated protein 2 (SKP2) is a key component of the SCF-type E3 ubiquitin ligase complex, which is critically involved in ErbB family-induced Akt ubiquitination, aerobic glycolysis and tumorigenesis. SKP2 is pivotal for reproduction, and SKP2-deficient mice show impaired ovarian development and reduced fertility.

METHODS

Here, we investigated the expression and function of SKP2 in human decidualization and its relation with RM. A total of 40 decidual samples were collected. Quantitative PCR analysis, western blot analysis and immunohistochemistry analysis were performed to analyze the differential expression of SKP2 between RM and control cells. For in vitro induction of decidualization, both HESCs (human endometrial stromal cells) cell line and primary ESCs (endometrial stromal cells) were used to analyze the effects of SKP2 on decidualization via siRNA transfection.

RESULTS

Compared to normal pregnant women, the expression of SKP2 was reduced in the decidual tissues from individuals with RM. After in vitro induction of decidualization, knockdown of SKP2 apparently attenuated the decidualization of HESCs and resulted in the downregulation of HOXA10 and FOXM1, which are essential for normal human decidualization. Moreover, our experiments demonstrated that SKP2 silencing reduced the expression of its downstream target GLUT1.

CONCLUSIONS

Our study indicates a functional role of SKP2 in RM: downregulation of SKP2 in RM leads to impaired decidualization and downregulation of GLUT1 and consequently predisposes individuals to RM.

Microstructures amplify carotenoid plumage signals in tanagers

Brilliantly-colored birds are a model system for research into evolution and sexual selection. Red, orange, and yellow carotenoid-colored plumages have been considered honest signals of condition; however, sex differences in feather pigments and microstructures are not well understood. Here, we show that microstructures, rather than carotenoid pigments, seem to be a major driver of male-female color differences in the social, sexually-dimorphic tanager genus Ramphocelus. We comprehensively quantified feather (i) color (using spectrophotometry), (ii) pigments (using liquid chromatography-mass spectrometry (LC-MS)), and (iii) microstructures (using scanning electron microscopy (SEM) and finite-difference time-domain (FDTD) optical modeling). Males have significantly more saturated color patches than females. However, our exploratory analysis of pigments suggested that males and females have concordant carotenoid pigment profiles across all species (MCMCglmm model, female:male ratio = 0.95). Male, but not female, feathers have elaborate microstructures which amplify color appearance. Oblong, expanded feather barbs in males enhance color saturation (for the same amount of pigment) by increasing the transmission of optical power through the feather. Dihedral barbules (vertically-angled, strap-shaped barbules) in males reduce total reflectance to generate "super black" and "velvet red" plumage. Melanin in females explains some, but not all, of the male-female plumage differences. Our results suggest that a widely cited index of honesty, carotenoid pigments, cannot fully explain male appearance. We propose that males are selected to evolve amplifiers-in this case, microstructures that enhance appearance-that are not necessarily themselves linked to quality.

Association of Tumor Necrosis Factor-α -308G>A, -238G>A and -376G>A polymorphisms with recurrent pregnancy loss risk in the Greek population

Background

Promoter region SNPs in TNF-α have been studied in association with Recurrent Pregnancy Loss (RPL) occurrence in various populations. Among them, −238G > A, −308G > A and − 376G > A have been frequently investigated for their potential role in recurrent abortions. The aim of the present study is to evaluate the correlation among TNF-α 238, TNF-α 308 and TNF-α 376 polymorphisms and recurrent pregnancy loss risk in Greek women.

Methods

This study included 94 Caucasian women with at least two miscarriages of unexplained aetiology, before the 20th week of gestation. The control group consisted of 89 Caucasian women of proven fertility, with no history of pregnancy loss. DNA samples were subjected to PCR amplification using specific primers. Sanger sequencing was applied to investigate the presence of TNF-α 238, TNF-α 308, TNF-α 376 polymorphisms in all samples.

Results

The TNF-α 238 and TNF-α 308 variants were both detected in RPL and control groups (7.45% vs 4.49 and 45.16% vs 36.73%, respectively), but with no statistically significant association (p-value 0.396 and 0.374, respectively). The TNF-α 376 variant was not detected at all in both control and RPL groups. When TNF-α 238 and TNF-α 308 genotypes were combined no association with RPL was detected (p-value = 0.694). In subgroup analysis by parity, RPL patients carrying the A allele reported less previous births.

Conclusions

This is the first study demonstrating TNF-α 238 and TNF-α 308 gene expression and the absence of TNF-α 376 variant in Greek women with RPL. However, no association emerged between each polymorphism studied and the occurrence of recurrent pregnancy loss. Accordingly, TNF-α -308G > A, −238G > A and -376G > A variants are not considered genetic markers for identifying women at increased risk of recurrent pregnancy loss in the Greek population.

The Physiology of Reproduction - Quo vadis?

The reproductive system in males and females reflects a highly dynamic underlying physiology. Yet our current understanding of this system is still largely based upon relatively simplistic snapshots of individual component cells and tissues. Gamete production as well as gonadal hormone synthesis and its influence are the manifestations of dynamic and redundant informational networks and processes, whose qualitative and quantitative dimensions, especially through development from embryo through puberty and adulthood into ageing, are still largely uncharted. Whilst the recent huge advances in molecular science have helped to describe the components of the reproductive system in ever greater detail, how these interact and function in space and time dimensions is still largely obscure. Recent developments in microfluidics, stem cell biology, and the integration of single-cell transcriptomics with tissue dynamics are offering possible methodological solutions to this issue. Such knowledge is essential if we are to understand not only the normal healthy functioning of this system, but also how and why it is affected in disease or by external impacts such as those from environmental endocrine disruptors, or in ageing. Moreover, operating within a complex network of other physiological systems, its integrational capacity is much more than the generation of male and female gametes and their roles in fertility and infertility; rather, it represents the underpinning support for health and well-being across the lifespan, through pregnancy, puberty, and adulthood, into old age.

Characterization of highly proliferative decidual precursor cells during the window of implantation in human endometrium

Pregnancy depends on the wholesale transformation of the endometrium, a process driven by differentiation of endometrial stromal cells (EnSC) into specialist decidual cells. Upon embryo implantation, decidual cells impart the tissue plasticity needed to accommodate a rapidly growing conceptus and invading placenta, although the underlying mechanisms are unclear. Here we characterize a discrete population of highly proliferative mesenchymal cells (hPMC) in midluteal human endometrium, coinciding with the window of embryo implantation. Single-cell transcriptomics demonstrated that hPMC express genes involved in chemotaxis and vascular transmigration. Although distinct from resident EnSC, hPMC also express genes encoding pivotal decidual transcription factors and markers, most prominently prolactin. We further show that hPMC are enriched around spiral arterioles, scattered throughout the stroma, and occasionally present in glandular and luminal epithelium. The abundance of hPMC correlated with the in vitro colony-forming unit activity of midluteal endometrium and, conversely, clonogenic cells in culture express a gene signature partially conserved in hPMC. Cross-referencing of single-cell RNA-sequencing data sets indicated that hPMC differentiate into a recently discovered decidual subpopulation in early pregnancy. Finally, we demonstrate that recurrent pregnancy loss is associated with hPMC depletion. Collectively, our findings characterize midluteal hPMC as novel decidual precursors that are likely derived from circulating bone marrow-derived mesenchymal stem/stromal cells and integral to decidual plasticity in pregnancy.

Recurrent pregnancy loss

Recurrent pregnancy loss is a distressing pregnancy disorder experienced by ~2.5% of women trying to conceive. Recurrent pregnancy loss is defined as the failure of two or more clinically recognized pregnancies before 20-24 weeks of gestation and includes embryonic and fetal losses. The diagnosis of an early pregnancy loss is relatively straightforward, although progress in predicting and preventing recurrent pregnancy loss has been hampered by a lack of standardized definitions, the uncertainties surrounding the pathogenesis and the highly variable clinical presentation. The prognosis for couples with recurrent pregnancy loss is generally good, although the likelihood of a successful pregnancy depends on maternal age and the number of previous losses. Recurrent pregnancy loss can be caused by chromosomal errors, anatomical uterine defects, autoimmune disorders and endometrial dysfunction. Available treatments target the putative risk factors of pregnancy loss, although the effectiveness of many medical interventions is controversial. Regardless of the underlying aetiology, couples require accurate information on their chances of having a baby and appropriate support should be offered to reduce the psychological burden associated with multiple miscarriages. Future research must investigate the pathogenesis of recurrent pregnancy loss and evaluate novel diagnostic tests and treatments in adequately powered clinical trials.

Systematic biological and proteomics strategies to explore the regulation mechanism of Shoutai Wan on recurrent spontaneous Abortion's biological network

ETHNOPHARMACOLOGICAL RELEVANCE

Shoutai Wan (STW) is a classic herbal formula for the treatment of recurrent spontaneous abortion (RSA), and clinical studies have shown the effectiveness of STW on RSA. However, the molecular mechanism of STW treatment of RSA is still unclear.

METHODS

(1) Animal experiments: The normal pregnancy model was established with CBA/J*BALB/C, and the RSA model was established by CBA/J*DBA/2. The RSA model CBA/J*DBA/2 pregnant mice were randomly divided into four groups (RSA model group, STW low, medium and high dose groups) according to the order of pregnancy, respectively. The drug administration starts from the first day of pregnancy to the 14th day of pregnancy. The embryo loss rate (ELR) of each group was calculated. (2) Proteomic analysis of decidual tissue: The total protein of decidual tissue of each group was isolated by solid phase pH gradient 2-DE technique. The differentially expressed protein spots were analyzed and identified by PDQuest images; the peptide quality fingerprinting (PMF) was obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Then, the proteins were identified by Mascot software searching, their functions were identified by bioinformatics strategy. (3) The expression of HSP27, α-enolase and Transferrin was detected by Western blotting and the expression of Annexin A2 and Transferrin was detected by immunohistochemistry. (4) The differential proteins and potential targets were analyzed by systematic biological strategy.

RESULTS

(1) Compared with the normal group, the ELR in the RSA model group was significantly higher (P < 0.01). Compared with the model group, the ELR in the STW high, medium dose groups was lower (P < 0.01). (2) A 2-DE map of the decidual tissue of the RSA model group, normal pregnancy group, STW low, medium and high dose groups was established. Thirty proteins were identified. (3) The results of western blot showed that the expression of HSP27 and a-enolase in the RSA model group was higher than that in the normal group, and the expression of transferrin was lower (P < 0.01). Compared with the model group, the expression of HSP27 and a-enolase in STW high, medium dose groups was decreased (P < 0.01); Compared with the model group, the expression of Transferrin in the STW high dose group was increased (P < 0.01). (5) A lot of RSA treatment-related targets, biological processes and pathways were found after the systematic biological analysis.

CONCLUSION

(1) STW may reduce the ELR of the RSA mice. (2) The results of proteomics suggest that RSA is a complex process involving multiple proteins. STW can regulate the expression of various proteins in the decidual tissue of RSA mice, suggesting that it can act on multiple targets. (3) The results of western blotting of HSP27, a-enolase, transferrin were consistent with the results of proteomic analysis. (4) STW may achieve therapeutic effects by interfering with the targets, biological processes and signaling pathways discovered in this study.

Combined hereditary thrombophilias are responsible for poor placental vascularization development and low molecular weight heparins (LMWH) prevent adverse pregnancy outcomes in these patients

BACKGROUND

Even though thrombophilias are associated with negative pregnancy outcomes (PO), there is not a consensus of when thrombophilias should be screened for, or how they affect placental vascularization during pregnancy. Therefore, the main aim of this study was to discover inherited thrombophilias (IHT) in the first trimester in women with otherwise no indications for thrombophilia screening, based on their vascularization parameters. LMWH treatment in improvement of placental vascularization and PO was also assessed. Finally, the classification of thrombophilias based on observed obstetric risks was proposed.

METHODS

Women were included in study based on their poor gestational sac and later utero-placental juncture vascularization signal and screening for inherited thrombophilias. LMWH were then initiated and Resistance index of Uterine artery (RIAU) was followed alongside PO (preterm birth, preeclampsia, placental abruption, intrauterine growth reduction). Study group consisted of women with combined inherited thrombophilias. Control group consisted of patients with inherited thrombophilias who have received LMWH therapy since pregnancy beginning.

FINDINGS

Out of 219 women, 93 had IHT, and 43 had combined IHT. All pregnancies both in both groups ended up with live births. Vaginal birth was more present in the control group (p < .001), and all women in study group delivered by CS. Premature birth was present in 8.4% of patients in control group, and in 32.55% of the patients in the study (p < .001). PE wasn't noted, and only 1 case of PA in control group. In the control group, 6.5% patients had IUGR, and 32.55% in the study group (p < .05). Based on RIAU and PO, thrombophilia categories were established: S (severe), MO (moderate), MI (mild) and L (low). Higher risk thrombophilias had higher RIAU later in the pregnancy, earlier pregnancy termination and Intrauterine Growth Reduction (IUGR).

CONCLUSIONS

Thrombophilias should be considered and screened when poor vascularization is noted early in the pregnancy with Doppler sonography. Intervention with LMWH prevents adverse PO in these patients.

Higher chromosomal abnormality rate in blastocysts from young patients with idiopathic recurrent pregnancy loss

OBJECTIVE

To determine whether the incidence of chromosomal abnormalities in blastocysts is higher in patients with idiopathic recurrent pregnancy loss (iRPL) who underwent preimplantation genetic testing for aneuploidy (PGT-A) than in those who underwent preimplantation genetic testing for monogenic defects (PGT-M).

DESIGN

Retrospective cohort study.

SETTING

University-affiliated reproductive center.

PATIENT(S)

A total of 62 patients with iRPL underwent 101 PGT-A cycles (iRPL group), and 212 patients underwent 311 PGT-M cycles (control group).

INTERVENTIONS(S)

Blastocyst biopsy and comprehensive chromosome screening technologies, including single-nucleotide polymorphism microarrays and next-generation sequencing.

MAIN OUTCOME MEASURE(S)

Incidence of chromosomal abnormalities in blastocysts and clinical miscarriage (CM) rate.

RESULT(S)

Stratification analysis by maternal age showed an increased incidence of chromosomal abnormalities in the iRPL group aged ≤35 years (48.9% vs. 36.9%), whereas no significant increase was found in the iRPL group aged >35 years (66.9% vs. 61.4%). After transfer of euploid embryos, women aged ≤35 years with iRPL exhibited an increased CM rate compared with the control group (26.1% vs. 3.1%).

CONCLUSION(S)

Young patients with iRPL have a significantly higher rate of chromosomal abnormalities in blastocysts compared with patients with no or sporadic CM. Although euploid embryos were transferred after PGT-A, young patients with iRPL had a higher CM rate, which may indicate that chromosomal abnormalities might not be the only causal factor for iRPL. Therefore, the role of PGT-A in iRPL still needs to be clarified.

circ-ZUFSP regulates trophoblasts migration and invasion through sponging miR-203 to regulate STOX1 expression

Recurrent spontaneous abortion (RSA), defined as two or more consecutive pregnancy losses before 12 weeks of gestation with or without previous live births. Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that play important roles in gene expression regulation and trophoblasts function during embryo development. This study aimed to evaluate the function mechanism of circRNAs regulating trophoblasts function in the occurrence and progression RSA. Through overexpression and down-regulation of circ-ZUFSP, we investigated the effect of circ-ZUFSP on the function of trophoblasts and found loss of circ-ZUFSP suppressed trophoblasts migration and invasion in vitro. Moreover, loss of circ-ZUFSP regulated trophoblasts migration and invasion via regulation of miR-203. Furthermore, STOX1 was revealed to a target of miR-203, and down-regulation of STOX1 reversed circ-ZUFSP enhanced cell invasion, suggesting that circ-ZUFSP might regulate STOX1 expression through sponging miR-203 in HTR-8/SVneo cells. In addition, low expression of circ-ZUFSP, STOX1 and high expression of miR-203 were testified in placental tissues of RSA mice. Our study demonstrated a molecular mechanism of circ-ZUFSP regulating trophoblasts migration and invasion, which might provide a novel indicator for early diagnosis and potential treatment of RSA.

Early pregnancy loss: the default outcome for fertilized human oocytes

Early pregnancy loss is by far the most frequent outcome of human reproduction. It occurs when despite the timely interaction of gametes and initiation of embryogenesis and implantation of the conceptus, pregnancy continuance fails. From a clinical perspective, early pregnancy loss represents a neglected but relevant issue because of the high incidence, the evolving and yet not fully elucidated mechanism, the possible association with other relevant medical conditions, and the potential psychological sequelae. Our growing understanding of the dialog established between the embryo and the endometrium provides new insights into the etiology of pregnancy loss. Aneuploidies as a cause of early pregnancy loss are known for a long time, but there is now evidence that endometrium is not a passive player. An active selection aimed at impeding implantation of unhealthy embryos actually occurs at the endometrial interface. The concept of selectivity is substituting the one of mere receptivity.

Combined presence of coagulation factor XIII V34L and plasminogen activator inhibitor 1 4G/5G gene polymorphisms significantly contribute to recurrent pregnancy loss in Serbian population

Background

Recurrent pregnancy loss (RPL) is a heterogeneous condition affecting up to 5% of women of reproductive age. Inherited thrombophilia have been postulated as one of the causes of RPL. Here we examined the prevalence of nine thrombophilic gene polymorphisms among women with history of recurrent miscarriages and fertile controls.

Methods

The study included 70 women with history of at least three early pregnancy losses and 31 fertile controls with no miscarriages. We investigated mutations in genes responsible for clotting and fibrinolysis, including factor V (FV) Leiden, FV H1299R, factor II (FII) G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T and A1298C, factor XIII (FXIII) V34L, plasminogen activator inhibitor-1 (PAI-1) 4G/5G and endothelial protein C receptor (EPCR) H1 and H3 haplotypes using reverse polymerase chain reaction ViennaLab cardiovascular disease StrippAssays.

Results

Our results showed no significant increase in prevalence of tested polymorphisms in women with RPL. However, relative risk for PRL among women heterozygous for FXIII V34L was 2.81 times increased (OR 2.81, 95% CI 1.15-6.87, P=0.023). Haplotype analysis showed that combined presence of high-risk genotypes for FXIII and PAI-1 significantly increases risk for RPL (OR 13.98, CI 95% 1.11-17.46, P=0.044).

Conclusions

This is the first study in Serbian population that investigated prevalence of FVR2, A1298C, FXIII V34L and EPCR gene variants. Compound heterozygosity for FXIII V34L and PAI-1 4G is significant risk factor for recurrent miscarriage. Our results should be viewed in context of small case-control study, so further large prospective studies are need for confirmation of our findings.

Recurrent pregnancy loss is associated with a pro-senescent decidual response during the peri-implantation window

During the implantation window, the endometrium becomes poised to transition to a pregnant state, a process driven by differentiation of stromal cells into decidual cells (DC). Perturbations in this process, termed decidualization, leads to breakdown of the feto-maternal interface and miscarriage, but the underlying mechanisms are poorly understood. Here, we reconstructed the decidual pathway at single-cell level in vitro and demonstrate that stromal cells first mount an acute stress response before emerging as DC or senescent DC (snDC). In the absence of immune cell-mediated clearance of snDC, secondary senescence transforms DC into progesterone-resistant cells that abundantly express extracellular matrix remodelling factors. Additional single-cell analysis of midluteal endometrium identified DIO2 and SCARA5 as marker genes of a diverging decidual response in vivo. Finally, we report a conspicuous link between a pro-senescent decidual response in peri-implantation endometrium and recurrent pregnancy loss, suggesting that pre-pregnancy screening and intervention may reduce the burden of miscarriage.

Metabolism of cholesterol and progesterone is differentially regulated in primary trophoblastic subtypes and might be disturbed in recurrent miscarriages

During pregnancy, extravillous trophoblasts (EVTs) invade the maternal decidua and remodel the local vasculature to establish blood supply for the growing fetus. Compromised EVT function has been linked to aberrant pregnancy associated with maternal and fetal morbidity and mortality. However, metabolic features of this invasive trophoblast subtype are largely unknown. Using primary human trophoblasts isolated from first trimester placental tissues, we show that cellular cholesterol homeostasis is differentially regulated in EVTs compared with villous cytotrophoblasts. Utilizing RNA-sequencing, gene set-enrichment analysis, and functional validation, we provide evidence that EVTs display increased levels of free and esterified cholesterol. Accordingly, EVTs are characterized by increased expression of the HDL-receptor, scavenger receptor class B type I, and reduced expression of the LXR and its target genes. We further reveal that EVTs express elevated levels of hydroxy-delta-5-steroid dehydrogenase 3 beta- and steroid delta-isomerase 1 (HSD3B1) (a rate-limiting enzyme in progesterone synthesis) and are capable of secreting progesterone. Increasing cholesterol export by LXR activation reduced progesterone secretion in an ABCA1-dependent manner. Importantly, HSD3B1 expression was decreased in EVTs of idiopathic recurrent spontaneous abortions, pointing toward compromised progesterone metabolism in EVTs of early miscarriages. Here, we provide insights into the regulation of cholesterol and progesterone metabolism in trophoblastic subtypes and its putative relevance in human miscarriage.

Endometrial Immune Dysfunction in Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) represents an unresolved problem for contemporary gynecology and obstetrics. In fact, it is not only a relevant complication of pregnancy, but is also a significant reproductive disorder affecting around 5% of couples desiring a child. The current knowledge on RPL is largely incomplete, since nearly 50% of RPL cases are still classified as unexplained. Emerging evidence indicates that the endometrium is a key tissue involved in the correct immunologic dialogue between the mother and the conceptus, which is a condition essential for the proper establishment and maintenance of a successful pregnancy. The immunologic events occurring at the maternal-fetal interface within the endometrium in early pregnancy are extremely complex and involve a large array of immune cells and molecules with immunoregulatory properties. A growing body of experimental studies suggests that endometrial immune dysregulation could be responsible for several, if not many, cases of RPL of unknown origin. The present article reviews the major immunologic pathways, cells, and molecular determinants involved in the endometrial dysfunction observed with specific application to RPL.

Integrative analysis of the forkhead box A2 (FOXA2) cistrome for the human endometrium

The pioneer forkhead box (FOX)A2 transcription factor is specifically expressed in the glands of the uterus, which are central to endometrial function and fertility. In mice, FOXA2 is a critical regulator of uterine gland development in the neonate and gland function in the adult. An integrative approach was used here to define the FOXA2 cistrome in the human endometrium. Genome-wide mapping of FOXA2 binding intervals by chromatin immunoprecipitation sequencing was performed using proliferative (P)- and midsecretory (MS)-phase endometrium and integrated with the transcriptome determined by RNA sequencing. Distinctive FOXA2 binding intervals, enriched for different transcription factor binding site motifs, were detected in the P and MS endometrium. Pathway analysis revealed different biologic processes regulated by genes with FOXA2 binding intervals in the P and MS endometrium. Thus, FOXA2 is postulated to regulate gene expression in concert with other transcription factors and impact uterine gland development and function in a cycle phase-dependent manner. Analyses also identified potential FOXA2-regulated genes that influence uterine receptivity, blastocyst implantation, and stromal cell decidualization, which are key events in pregnancy establishment.-Kelleher, A. M., Behura, S. K., Burns, G. W., Young, S. L., DeMayo, F. J., Spencer, T. E. Integrative analysis of the forkhead box A2 (FOXA2) cistrome for the human endometrium.