ENO1 promotes trophoblast invasion regulated by E2F8 in recurrent miscarriage.

Recurrent miscarriage (RM) is related to the dysfunction of extravillous trophoblast cells (EVTs), but the comprehensive mechanisms remain largely unexplored. We analyzed single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing and microarray datasets obtained from Gene Expression Omnibus (GEO) database to explore the hub genes in the mechanisms of RM. We identified 1724 differentially expressed genes (DEGs) in EVTs from the RM, and they were all expressed along the trajectory of EVTs. These DEGs were associated with hypoxia and glucose metabolism. Single-cell Regulatory Network Inference and Clustering (SCENIC) analysis revealed that E2F transcription factor (E2F) 8 (E2F8) was a key transcription factor for these DEGs. And the expression of ENO1 can be positively regulated by E2F8 via RNA sequencing analysis. Subsequently, we performed immunofluorescence assay (IF), plasmid transfection, western blotting, chromatin immunoprecipitation (ChIP), real-time quantitative polymerase chain reaction (qRT-PCR), and transwell assays for validation experiments. We found that the expression of alpha-Enolase 1 (ENO1) was lower in the placentas of RM. Importantly, E2F8 can transcriptionally regulate the expression of ENO1 to promote the invasion of trophoblast cells by inhibiting secreted frizzled-related protein 1/4 (SFRP1/4) to activate Wnt signaling pathway. Our results suggest that ENO1 can promote trophoblast invasion via an E2F8-dependent manner, highlighting a potential novel target for the physiological mechanisms of RM.

MicroRNA­155­5p inhibits trophoblast cell proliferation and invasion by disrupting centrosomal function.

Recurrent miscarriage is used to refer to more than three pregnancy failures before 20 weeks of gestation. Defective trophoblast cell growth and invasion are frequently observed in recurrent miscarriage. Several microRNAs (miRs), including miR­155­5p, are aberrantly upregulated in recurrent miscarriage; however, the underlying molecular mechanisms remain unclear. The centrosome orchestrates microtubule networks and coordinates cell cycle progression. In addition, it is a base for primary cilia, which are antenna­like organelles that coordinate signaling during development and growth. Thus, deficiencies in centrosomal functions can lead to several disease, such as breast cancer and microcephaly. In the present study, the signaling cascades were analyzed by western blotting, and the centrosome and primary cilia were observed and analyzed by immunofluorescence staining. The results showed that overexpression of miR­155­5p induced centrosome amplification and blocked primary cilia formation in trophoblast cells. Notably, centrosome amplification inhibited trophoblast cell growth by upregulating apoptotic cleaved­caspase 3 and cleaved­poly (ADP­ribose) polymerase in miR­155­5p­overexpressing trophoblast cells. In addition, overexpression of miR­155­5p inhibited primary cilia formation, thereby inhibiting epithelial­mesenchymal transition and trophoblast cell invasion. All phenotypes could be rescued when cells were co­transfected with the miR­155­5p inhibitor, thus supporting the role of miR­155­5p in centrosomal functions. It was also found that miR­155­5p activated autophagy, whereas disruption of autophagy via the depletion of autophagy­related 16­like 1 alleviated miR­155­5p­induced apoptosis and restored trophoblast cell invasion. In conclusion, the present study indicated a novel role of miR­55­5p in mediating centrosomal function in recurrent miscarriage.

Kisspeptin prevents pregnancy loss by modulating the immune microenvironment at the maternal-fetal interface in recurrent spontaneous abortion.

PROBLEM: Immune factors are crucial in the development of recurrent spontaneous abortion (RSA). This study aimed to investigate whether kisspeptin regulates immune cells at the maternal-fetal interface and whether G protein-coupled receptor 54 (GPR54) is involved in this process, through which it contributes to the pathogenesis of RSA. METHOD OF STUDY: Normal pregnancy (NP) (CBA/J × BALB/c) and RSA (CBA/J × DBA/2) mouse models were established. NP mice received tail vein injections of PBS and KP234 (blocker of kisspeptin receptor), whereas RSA mice received PBS and KP10 (active fragment of kisspeptin). The changes in immune cells in mouse spleen and uterus were assessed using flow cytometry and immunofluorescence. The expression of critical cytokines was examined by flow cytometry, ELISA, Western blotting, and qPCR. Immunofluorescence was employed to detect the coexpression of FOXP3 and GPR54. RESULTS: The findings revealed that the proportion of Treg cells, MDSCs, and M2 macrophages in RSA mice was lower than that in NP mice, but it increased following the tail vein injection of KP10. Conversely, the proportion of these cells was reduced in NP mice after the injection of KP234. However, the trend of γδT cell proportion change is contrary to these cells. Furthermore, FOXP3 and GPR54 were coexpressed in mouse spleen and uterus Treg cells as well as in the human decidua samples. CONCLUSION: Our results suggest that kisspeptin potentially participates in the pathogenesis of RSA by influencing immune cell subsets at the maternal-fetal interface, including Treg cells, MDSC cells, γδT cells, and M2 macrophages.

Zishen Yutai Pills Promote Angiogenesis at the Maternal-Fetal Interface in Recurrent Spontaneous Abortion Mice by Regulating miR-187/VEGF Axis.

Ethnopharmacological Relevance: Zishen Yutai pills (ZYP), a traditional Chinese patent medicine, was listed in China in 1981. It is composed of 15 traditional Chinese medicines and has the effects of regulating menstruation, helping pregnancy, and preventing abortion. In clinical practice, it is effective in preventing habitual and threatened miscarriages, and continuing to explore its mechanism of action is very meaningful research. Aim of the Study: To explore the possible mechanism of ZYP promoting angiogenesis at the maternal-fetal interface in recurrent spontaneous abortion (RSA). Materials and Methods: In vitro experiments, placental trophoblast cells (PTCs) were isolated from the placental tissue of RSA mice and divided into six groups: Control group, Model group, ZYP group, miR-187 inhibitor NC group, miR-18 7 inhibitor group, and miR-187 inhibitor+ZYP group. Cell viability and cell cycle were measured using CCK8 and flow cytometry, respectively. The expression levels of miR-187, VEGF, VEGF-R1, and VEGF-R2 were measured using RT-qPCR, WB, and IF staining. Animal experiments first establish an RSA mice model (CBA/J × DBA/2) and then randomly divide the mice into four groups (n=10): normal pregnancy group, RSA model group, ZYP group, and progesterone capsule group. Observed the changes in embryo absorption rate, pathological morphology of decidual tissue, and ultrastructure of vascular endothelial cells in each group of mice. RT-qPCR, WB, and IF staining methods were used to determine the expression of miR-187, VEGF, VEGF-R1, and VEGF-R2. Results: In vitro, ZYP promoted the viability of PTCs and regulated their cell cycle, and ZYP down-regulated miR-187, up-regulated VEGF, VEGF-R1 and VEGF-R2 levels. miR-187 inhibitor showed the same effects, and further ZYP intervention enhanced the effects. In vivo, ZYP remarkably reduced embryo resorption rates, and improved the pathological morphology of decidual tissues and ultrastructure of vascular endothelial cells. Moreover, ZYP down-regulated miR-187, up-regulated VEGF, VEGF-R1 and VEGF-R2. Conclusion: In summary, ZYP can regulate the expression of VEGF via miR-187, then promote the angiogenesis at the maternal-fetal interface, and playing a therapeutic role in RSA.

JPT2 Affects Trophoblast Functions and Macrophage Polarization and Metabolism, and Acts as a Potential Therapeutic Target for Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is a pregnancy-related condition with complex etiology. Trophoblast dysfunction and abnormal macrophage polarization and metabolism are associated with RSA; however, the underlying mechanisms remain unknown. Jupiter microtubule-associated homolog 2 (JPT2) is essential for calcium mobilization; however, its role in RSA remains unclear. In this study, it is found that the expression levels of JPT2, a nicotinic acid adenine dinucleotide phosphate-binding protein, are decreased in the villous tissues of patients with RSA and placental tissues of miscarried mice. Mechanistically, it is unexpectedly found that abnormal JPT2 expression regulates trophoblast function and thus involvement in RSA via c-Jun N-terminal kinase (JNK) signaling, but not via calcium mobilization. Specifically, on the one hand, JPT2 deficiency inhibits trophoblast adhesion, migration, and invasion by inhibiting the JNK/atypical chemokine receptor 3 axis. On the other hand, trophoblast JPT2 deficiency contributes to M1 macrophage polarization by promoting the accumulation of citrate and reactive oxygen species via inhibition of the JNK/interleukin-6 axis. Self-complementary adeno-associated virus 9-JPT2 treatment alleviates embryonic resorption in abortion-prone mice. In summary, this study reveals that JPT2 mediates the remodeling of the immune microenvironment at the maternal-fetal interface, suggesting its potential as a therapeutic target for RSA.

Role of increased IGFBP2 in trophoblast cell proliferation and recurrent spontaneous abortion development: A pilot study.

Recurrent spontaneous abortion (RSA) is a serious condition that adversely affects women's health. Differentially expressed proteins (DEPs) in plasma of patients experiencing RSA is helpful to find new therapeutic targets and identified with mass spectrometry. In 57 DEPs, 21 were upregulated and 36 were downregulated in RSA. Gene ontology analyses indicated that identified DEPs were associated with cell proliferation, including significantly downregulated insulin-like growth factor binding protein 2 (IGFBP2). Immunohistochemical result using clinical decidual tissues also showed that IGFBP2 expression was significantly decreased in RSA trophoblasts. Cell proliferation assay indicated that IGFBP2 treatment increased the proliferation and mRNA expressions of PCNA and Ki67 in trophoblast cells. Transcriptome sequencing experiments and Kyoto Encyclopedia of Genes and Genomes analyses revealed that gene expression for components in PI3K-Akt pathway in trophoblasts was significantly upregulated following IGFBP2 treatment. To confirm bioinformatics findings, we did cell-based experiments and found that treatment of inhibitors for insulin-like growth factor (IGF)-1 receptor-PI3K-Akt pathway significantly reduced IGFBP2-induced trophoblast cell proliferation and mRNA expressions of PCNA and Ki67. Our findings suggest that IGFBP2 may increase trophoblast proliferation through the PI3K-Akt signaling pathway to affect pregnancy outcomes and that IGFBP2 may be a new target for future research and treatment of RSA.

MicroRNA mediated regulation of oxidative stress and cytokines in Chlamydia trachomatis-infected recurrent spontaneous abortion: A case-control study.

PROBLEM: Increased oxidative stress (OS) and inflammatory responses are major underlying factors behind Chlamydia trachomatis-associated recurrent spontaneous abortion (RSA). miRNAs are known to regulate inflammation and OS and their dysregulation has been associated with compromised pregnancies. Therefore, aim of this study was to investigate the expression/correlation of OS biomarkers, cytokines and miRNAs in C. trachomatis-associated RSA. METHOD OF STUDY: Urine and non-heparinized blood samples were collected from RSA patients with history of >3 consecutive abortions (cases) and non-pregnant women with history of >2 successful deliveries (controls) attending Department of Obstetrics and Gynaecology, Safdarjung hospital, New Delhi. C. trachomatis detection was done in urine by PCR. miRNA expression was studied by microarray analysis and validated by real time-PCR. Evaluation of cytokines and antioxidant genes expression were done by real-time PCR. Level of OS biomarkers 8-hydroxy guanosine (8-OHdG) and 8-isporostane (8-IP) were measured by ELISA. RESULTS: Fifty circulating miRNAs were differentially expressed in infected patients compared with controls. Of these, four were overexpressed and 46 downregulated. Thirteen differentially expressed circulating miRNAs were selected to validate microarray results. miRs-8069, -3663-3p showed maximum upregulation/downregulation in infected versus control group. Expression of cytokines (IL-8, TNF-α, IFN-γ), antioxidant genes SOD2 and OS biomarkers (8-OHdG,8-IP) were increased while SOD1 was decreased in infected patients. miR-8069 showed significant positive correlation with cytokines, SOD2, 8-OHdG and 8-IP. miR-3663-3p showed significant positive correlation with SOD1. CONCLUSIONS: Overall results indicate circulating miRNAs are involved in pathogenesis of C. trachomatis-associated RSA and are potential modulators of cytokine signalling and OS in infected RSA.

Multi-omics reveals the switch role of abnormal methylation in the regulation of decidual macrophages function in recurrent spontaneous abortion.

RSA, recurrent spontaneous abortion, often causes serious physical damage and psychological pressure in reproductive women with unclarified pathogenesis. Abnormal function of decidual cells and aberrant DNA methylation have been reported to cause RSA, but their association remains unclear. Here, we integrated transcriptome, DNA methylome, and scRNA-seq to clarify the regulatory relationship between DNA methylation and decidual cells in RSA. We found that DNA methylation mainly influenced the function of decidual macrophages (DMs), of which four hub genes, HLA-A, HLA-F, SQSTM1/P62, and Interferon regulatory factor 7 (IRF7), related to 22 hypomethylated CpG sites, regulated 16 hub pathways to participate in RSA pathogenesis. In particular, using transcription factor analysis, it is suggested that the upregulation of IRF7 transcription was associated with enhanced recruitment of the transcription factor STAT1 by the hypomethylated promoter region of IRF7. As the current research on DNA methylation of macrophages in the uterine microenvironment of RSA is still blank, our systematic picture of abnormal DNA methylation in regulating DM function provides new insights into the role of DNA methylation in RSA occurrence, which may aid in further prevention and treatment of RSA.

The effect and mechanism of low-molecular-weight heparin on the decidualization of stromal cells in early pregnancy.

OBJECTIVE: This study aimed to analyze the effect of low-molecular-weight heparin (LMWH) on the decidualization of stromal cells in early pregnancy and explore the effect of LMWH on pregnancy outcomes. METHODS: Recurrent spontaneous abortion (RSA) mouse model (CBA/J × DBA/2) and normal pregnant mouse model (CBA/J × BALB/c) were established. The female mice were checked for a mucus plug twice daily to identify a potential pregnancy. When a mucus plug was found, conception was considered to have occurred 12 h previously. The pregnant mice were divided randomly into a normal pregnancy control group, an RSA model group, and an RSA + LMWH experimental group (n = 10 mice in each group). Halfway through the 12th day of pregnancy, the embryonic loss of the mice was observed; a real-time quantitative polymerase chain reaction was used to detect the messenger ribonucleic acid (mRNA) expressions of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) in the decidua of the mice. Additionally, the decidual tissues of patients with RSA and those of normal women in early pregnancy who required artificial abortion were collected and divided into an RSA group and a control group. Decidual stromal cells were isolated and cultured to compare cell proliferation between the two groups, and cellular migration and invasion were detected by membrane stromal cells. Western blotting was used to detect the protein expressions of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteinase- (MMP) 2, and MMP-7 in stromal cells treated with LMWH. RESULTS: Compared with the RSA group, LMWH significantly reduced the pregnancy loss rate in the RSA mice (p < 0.05). Compared with the RSA group, the LMWH + RSA group had significantly higher expression levels of PRL and IGFBP1 mRNA (p < 0.01). LMWH promoted the proliferation, migration, and invasion of human decidual stromal cells; compared with the control group, the expression levels of MMP-2, MMP-7, cyclin D1, and PCNA proteins in the decidual stromal cells of the LMWH group increased (p < 0.05). CONCLUSIONS: The use of LMWH can improve pregnancy outcomes by enhancing the proliferation and migration of stromal cells in early pregnancy and the decidualization of stromal cells.

MANF Promotes Unexplained Recurrent Miscarriages by Interacting with NPM1 and Downregulating Trophoblast Cell Migration and Invasion.

Dysplasia and invasive defects in early trophoblasts contribute to unexplained recurrent miscarriages (URMs). Mesencephalic astrocyte-derived neurotrophic factor (MANF) inhibits migration and invasion in some cancer cells, but its role in pregnancy-related diseases remains unresolved. Here, we found that MANF levels in the peripheral blood and aborted tissue of URM women were higher than in normal controls, irrespective of pregnancy or miscarriage. We confirm the interaction between MANF and nucleophosmin 1 (NPM1) in trophoblasts of URM patients, which increases the ubiquitination degradation of NPM1, leading to upregulation of the p53 signaling pathway and inhibition of cell proliferation, migration, and invasion ability. Using a URM mouse model, we found that MANF downregulation resulted in reduced fetal resorption; however, concomitant NPM1 downregulation led to increased abortion rates. These data indicate that MANF triggers miscarriage via NPM1 downregulation and p53 activation. Thus, MANF downregulation or disruption of the MANF-NPM1 interaction could be targets for URM therapeutics.

Ultrastructural cilia defects in multi-ciliated uterine glandular epithelial cells from women with reproductive failure.

In brief: The causes of subfertility and recurrent pregnancy loss are often unclear. This study shows that endometrial gland cilia from women with subfertility have ultrastructural defects. Abstract: Endometrial glands secrete products into the endometrium and are necessary for embryo implantation and successful pregnancy. However, structural and functional abnormalities in endometrial gland cilia from women with reproductive failure remain poorly understood. This was a cross-sectional study where endometrial biopsies were collected at days 19-23 of the menstrual cycle from women with unexplained recurrent pregnancy loss (n = 15), unexplained subfertility (n = 11) or from egg donor control participants (n = 10). Endometrial gland cilia ultrastructure was imaged by transmission electron microscopy and cilia defects assessed by an electron-microscopist from a national primary ciliary dyskinesia diagnostic centre. Endometrial glands were isolated, and the cilia beat frequency recorded by high speed video. Subfertile women have proportionately lower ultrastructurally normal cilia (P < 0.05); higher frequency of absent dynamin arms (P < 0.01) or inner arm defects (P < 0.01) and lower cilia beat frequency (P < 0.05). The mechanisms underlying these obversions have yet to be determined. Recent studies have identified cilia related gene expression changes associated with reproductive failure and this study adds to the growing body of literature revealing structural and functional changes. The observation that cilia defects occurred at a higher frequency in endometrial glands of subfertile women raises the question of its mechanistic role in implantation.

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.

Downregulation of CRHBP is associated with trophoblast invasion inhibition in recurrent pregnancy loss.

In brief: Corticotropin-releasing hormone binding protein (CRHBP) is fundamental to the stress response and plays an important role in parturition during pregnancy. This study shows that abnormal CRHBP expression could be an early warning sign of recurrent pregnancy loss and that CRHBP knockdown could suppress HTR8/SVneo cell invasion by the PKC signaling pathway via interacting with CRH receptor 2. Abstract: Trophoblast invasion is critical for placentation and pregnancy success. Trophoblast dysfunction results in many pregnancy complications, including recurrent pregnancy loss (RPL). Corticotropin-releasing hormone binding protein (CRHBP) is fundamental to the stress response and plays an important role in parturition during pregnancy via binding with CRH. To further characterize its function in early pregnancy, we explored the expression of CRHBP in villi during early pregnancy. Compared with normal pregnant women, we demonstrated that the expression of CRHBP decreased in the trophoblasts and villi in RPL patients and that knockdown of CRHBP expression could suppress HTR8/SVneo cell invasion significantly. Our further exploration indicated that the capacity of CRHBP for regulating trophoblast invasion was associated with the PKC signaling pathway via interacting with CRH receptor 2. These findings might provide a new fundamental mechanism for successful pregnancy and a new diagnostic and therapeutic target for RPL.

Efficacy of mesenchymal stromal cells in the treatment of unexplained recurrent spontaneous abortion in mice: An analytical and systematic review of meta-analyses.

OBJECTIVES: Unexplained recurrent spontaneous abortion (URSA) remains an intractable reproductive dilemma due to the lack of understanding of the pathogenesis. This study aimed to evaluate the preclinical evidence for the mesenchymal stromal cell (MSC) treatment for URSA. METHODS: A meticulous literature search was independently performed by two authors across the Cochrane Library, EMBASE, and PubMed databases from inception to April 9, 2023. Each study incorporated was assessed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) risk of bias tool. The amalgamated standardized mean difference (SMD) accompanied by 95% confidence interval (CI) were deduced through a fixed-effects or random-effects model analysis. RESULTS: A total of ten studies incorporating 140 mice were subjected to data analysis. The MSC treatment yielded a significant reduction in the abortion rate within the URSA model (OR = 0.23, 95%CI [0.17, 0.3], P<0.00001). Moreover, it elicited a positive modulatory impact on the expression profiles of several inflammatory cytokines in the decidual tissue of URSA murine models, inclusive of IL4 (SMD 1.63, 95% CI [0.39, 2.86], P = 0.01), IL10 (SMD 1.60, 95% CI [0.58, 2.61], P = 0.002), IFN-γ (SMD -1.66, 95%CI [-2.79, -0.52], P = 0.004), and TNF-α (SMD -1.98, 95% CI [-2.93, -1.04], P< 0.0001). Subgroup analyses underscored that the administration mode of intraperitoneal and uterine horn injections, and sources of bone MSCs and adipose-derived MSCs contributed positively to the expression of IL4, IL10, and decreased the expression of IFN-γ in decidual tissue of URSA (P<0.05). Conversely, the tail vein injections subgroup was observed with no statistical significance (P>0.05). CONCLUSIONS: The findings underscore the considerable potential of MSCs in URSA therapy. Nonetheless, the demand for enhanced transparency in research design and direct comparisons between various MSC sources and administration routes in URSA is paramount to engendering robust evidence that could pave the way for successful clinical translation.

LncRNA AOC4P recruits TRAF6 to regulate EZH2 ubiquitination and participates in trophoblast glycolysis and M2 macrophage polarization which is associated with recurrent spontaneous abortion.

During embryo implantation, trophoblast cells rely on large amounts of energy produced by glycolysis for their rapid growth and invasion. The disorder of trophoblast metabolism may lead to recurrent spontaneous abortion (RSA). Lactate, which is produced by the glycolysis of trophoblast cells during early pregnancy, can promote the polarization of M2 macrophages and maintain an anti-inflammatory environment at the maternal-fetal interface. Our study found that amine oxidase copper-containing 4 pseudogene (AOC4P) was abnormally increased in villi from RSA patients. It inhibited the glycolysis of trophoblast cells and thus hindered the polarization of M2 macrophages. Further studies showed that AOC4P combines with tumor necrosis factor receptor-associated factor 6 (TRAF6) to upregulate TRAF6 expression. TRAF6 acted as an E3 ubiquitin ligase to promote ubiquitination and degradation of zeste homolog 2 (EZH2). These results provided new insights into the important role played by AOC4P at the maternal-fetal interface.

HNRNPC mediated m6A methylation of 5-methyltetrahydrofolate-homocysteine methyltransferase and involved in the occurrence of RSA.

N6-methyladenosine methylated modification has been shown to play roles in recurrent spontaneous abortion. We aimed to explore role of heterogeneous nuclear ribonucleoprotein C in the occurrence of recurrent spontaneous abortion. We collected embryonic villous tissues from 3 patients with recurrent spontaneous abortion (RSA group) and 3 normal control pregnancy patients. Methylated RNA immunoprecipitation sequencing, RNA sequencing, methylated RNA immunoprecipitation quantitative PCR were conducted to detect the differentially expressed m6A methylation modification gene and regulatory gene in patients with recurrent spontaneous abortion. Methylated RNA immunoprecipitation sequencing and RNA sequencing results showed that the mRNA expression level of heterogeneous nuclear ribonucleoprotein C significantly decreased in RSA group and mRNA expression level of 5-methyltetrahydrofolate-homocysteine methyltransferase increased. Real-time quantitative PCR confirmed the differential expression of heterogeneous nuclear ribonucleoprotein C and 5-methyltetrahydrofolate-homocysteine methyltransferase. Methylated RNA immunoprecipitation quantitative PCR result showed that mRNA m6A modification level of 5-methyltetrahydrofolate-homocysteine methyltransferase decreased in RSA group. The results of western blotting, real-time quantitative PCR, immunofluorescence, matrigel invasion and wound healing assays indicated that heterogeneous nuclear ribonucleoprotein C might regulate the expression of 5-methyltetrahydrofolate-homocysteine methyltransferase by mediating m6A modification, thereby reducing the proliferation and migration of trophoblast cell line, ultimately leading to the occurrence of recurrent spontaneous abortion.

FKBP5 regulates trophoblast-macrophage crosstalk in recurrent spontaneous abortion through PI3K/AKT and NF-κB signaling pathways.

FK506-binding protein 5 (FKBP5) contributes to many diseases; However, it remains unclear whether FKBP5 is relevant to recurrent spontaneous abortion (RSA) and the mechanisms by which it is involved in maternal-fetal immunological tolerance. Placental tissue was collected in women with normal pregnancy and RSA and examined for FKBP5 expression. Human trophoblast cell lines and THP-1-derived M0 macrophages were used to explore the role of FKBP5 in RSA and its mechanism. The role of FKBP5 on pregnancy outcomes was assessed using a mouse model of miscarriage. This study found that upregulation of FKBP5 at the placental interface is involved in the pathogenesis of RSA by depressing trophoblast function and promoting M1-type macrophage polarization. First, FKBP5 expression was upregulated in the villi of RSA, and FKBP5 regulated trophoblast function by inhibiting HAPLN1 expression through suppression of PI3K/AKT signaling. In addition, FKBP5 inhibited trophoblast IL-6 secretion by suppressing PI3K/AKT signaling, thereby promoting macrophage polarization toward the M1 phenotype. Meanwhile, FKBP5 was significantly elevated in decidual macrophages from patients with RSA and promoted M1 macrophage polarization via ROS/NF-κB signaling and further inhibited trophoblast function. Finally, FKBP5 inhibitors improved embryo resorption rate in miscarried mice. In conclusion, FKBP5 is essential in maintaining pregnancy and trophoblast-macrophage crosstalk in the maternal-fetal interface, which may be a potential target for diagnosing and treating RSA.

Pyruvate dehydrogenase kinase 1 regulates the function of human decidual natural killer cells.

PROBLEM: Pyruvate dehydrogenase kinase 1 (PDK1) is an important enzyme for immune cell development. However, PDK1's role in human decidual natural killer (dNK) cells remains largely unknown. METHODS OF STUDY: PDK1 expression in dNK cells from patients with recurrent spontaneous abortions (RSA) and age-matched healthy controls was analyzed by qRT-PCR, western bolt and flow cytometry. Moreover, dNK cells were treated with PDK1 inhibitor or the PDK1 siRNA followed by functional assays. RESULTS: The dNK cells from patients who underwent RSAs had higher mRNA expression and increased protein of PDK1, perforin (PRF1), Granzyme B (GZMB), IFN-γ (IFNG), and CD107a expression compared to dNK cells from age-matched healthy controls. Perforin, Granzyme B, IFN-γ and CD107a expression levels in dNK cells were down-regulated when dNK cells were treated with a PDK1 inhibitor. As measured by the 51 Cr release assay, the killing activity of dNK cells was found to be decreased. We also demonstrated that PDK1 blockade could up-regulate the migration and adhesion of dNK cells. Furthermore, PDK1 inhibition reduced the glycolysis of dNK cells. CONCLUSION: This study suggested that PDK1 plays an important role in regulating dNK cell functions and human RSA.

A Study of the Predictive Value of Treg and Th1/Th2 Cytokines on Pregnancy Outcome in Patients with Recurrent Pregnancy Loss.

Objectives: To investigate the influence of helper T cell type 1 (Th1)/Th2 cytokines and Treg cells on the pregnancy outcome of patients with recurrent pregnancy loss (RPL) and to reveal the predictive value of their combination on the pregnancy outcome. Methods: The 165 RPL patients admitted to the Reproductive Medicine Department of the Second Hospital of Lanzhou University from September 2019 to June 2021 served as the research subjects for the study. The subjects comprised a live birth group (102 patients) or a non-live birth group (63 patients) based on their pregnancy outcomes. All patients were tracked through the end of pregnancy. Flow cytometry was applied to determine Treg and Th1/Th2 cytokine levels in the peripheral blood of patients without pregnancy. Results: The levels of interleukin-6 (IL-6), IL-2, IL-10, and Treg in the RPL live birth group were significantly higher than those in the non-live birth group. The ratio of TNF - α/ IL-6, NF-α/ IL-10, IFN- γ/ IL-6, IFN- γ/ IL-10 in the non-live birth group increased significantly. The area under the curve (AUC) of Th1/Th2 cytokines combined with Treg cells was 0.786 (95% CI: 0.712-0.860), the specificity was 76.2%, and the sensitivity was 74.5%. Conclusion: Treg and Th1/Th2 cytokines showed a predictive ability for the pregnancy outcome of patients with recurrent pregnancy loss and their higher combined predictive efficacy. Meanwhile, in the Th1/Th2 immune response, its ratio was more important than the expression of a single cytokine.

Crosstalk between Placental Trophoblast and Decidual Immune Cells in Recurrent Miscarriage.

Recurrent miscarriage (RM) is a pregnancy complication associated with dysregulation of the maternal-fetal interface. We aimed to identify dysfunctional interactions between trophoblast cells and decidual immune cells in RM. We downloaded single-cell RNA sequencing (scRNA-seq) datasets (GSE214607) from the Gene Expression Omnibus (GEO) datasets for further analysis using the R software. The data comprised of paired placental and decidual tissues, including those from patients diagnosed with RM and matched healthy controls. A total of 22976 cells were identified in 11 cell types, including trophoblasts, immune cells, and other cells. We divided trophoblast cells into three types and analyzed their interactions with decidual immune cells. Additionally, we re-clustered NK&T cells and macrophages, identified differentially expressed genes (DEGs), enriched their functions, and compared the cell interactions with trophoblast cells in each cell type. Our single-cell atlas of the maternal-fetal interface revealed alterations in the cellular organization of the decidua and placenta, cell type-specific transcriptome, and cell communication between immune and non-immune cells in RM, which are critical for illuminating the pathophysiology of RM.