Recent Advances in Treatment of Recurrent Spontaneous Abortion

MTHFD2: A metabolic checkpoint altering trophoblast invasion and migration by remodeling folate-nucleotide metabolism in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) affects female reproduction worldwide, yet its pathological mechanisms are still unclear. It has been reported that cellular metabolism reprogramming is a critical step for trophoblasts during embryo implantation. Herein, MTHFD2 was recognized as a key metabolic checkpoint attributed to RSA occurrence. This work figured out that the expression level of MTHFD2 was significantly inhibited in villus tissues from RSA patients, suggesting the potential role of MTHFD2 in RSA occurrence. Moreover, MTHFD2 knockdown impaired cellular folate-nucleotide metabolism, induced the accumulation of AICAR, and thereby impairing the EMT process to inhibit the invasion and migration of trophoblasts Besides, the AICAR accumulation further activated the downstream AMPK which deactivated the JAK/STAT/Slug pathway and ultimately deactivated the EMT process. Using a mouse model, MTHFD2 inhibition was observed to induce embryo implantation failure in vivo. Our results highlighted MTHFD2 as a metabolic checkpoint that remodeled folate-nucleotide metabolism to regulate the EMT process and ultimately altered the migration and invasion of trophoblasts in RSA occurrence. Our findings suggested that MTHFD2 was a promising therapeutic target in recurrent spontaneous abortion treatment.

Baicalein prevents pregnancy loss by maintaining regulatory T cell activation through inhibition of the TLR4/NF-κB signaling pathway

INTRODUCTION

Unexplained recurrent spontaneous abortion (URSA) involves multifactorial etiologies, with regulatory T cells (Tregs) playing a pivotal role in maintaining immune tolerance during pregnancy. Baicalein, a flavonoid from Scutellaria baicalensis, exhibits anti-inflammatory and immunomodulatory properties. This study evaluates baicalein's therapeutic potential in mitigating URSA via the TLR4/NF-κB signaling pathway.

METHODS

A URSA mouse model was used, and baicalein was administered intraperitoneally. Pregnancy outcomes, abortion rates, and placental morphology were assessed on gestational day 14 (G14). Treg cells were quantified via flow cytometry, and gene/protein expression levels were analyzed by immunohistochemistry, Western blotting, and real-time PCR. In vitro experiments on ihESCs further investigated the role of the TLR4/NF-κB pathway.

RESULTS

Baicalein reduced abortion rates from 33.3 % in URSA mice to 21.6 % (low dose) and 14.8 % (high dose), improved embryonic development by altering placental structure and decidual morphology, and reduced inflammation at the maternal-fetal interface. It expanded Treg cells and enhanced the expression of IGFBP-1 and PRL, markers of endometrial decidualization, and decreased TLR4, p-P65, and P65 expression. In vitro, baicalein's effects were abrogated by TLR4 inhibition, confirming pathway specificity.

DISCUSSION

Baicalein improved pregnancy outcomes by enhancing Treg function and promoting decidualization via TLR4/NF-κB pathway inhibition. These findings highlight baicalein's potential as a therapeutic agent for URSA.

Role of Ca2+/calmodulin and PI3K/AKT signaling pathways and active ingredients of BaoTaiYin in treatment of recurrent miscarriage

Introduction

BaoTaiyin (BTY) is a traditional Chinese medicine decoction. It has been used to treat recurrent miscarriage (RM). However, there are no comprehensive systematic studies to identify the chemical compositions of BTY and molecular mechanisms on RM. Finding the chemical components of BTY and clarifying the underlying processes in the treatment of RM were the goals of the study.

Methods

We used ultra-high-performance liquid chromatography coupled with triple quadruple time-of-flight tandem mass spectrometry to analyze the chemical components of BTY, network analysis to predict the pharmacological effects of the identified active ingredients, and cell experiments to identify potential molecular mechanisms.

Results

We found 12 active ingredients among 61 components identified in BTY. These identified activities were linked to regulatory effects on 127 key signaling pathways, targeting 107 proteins. Through network analysis, we determined that insulin-like growth factor 1 receptor, matrix metalloproteinases, PI3K, and STAT3 may be the core targets of BTY's therapeutic effects on RM. We further explored this mechanism to find that aqueous extracts of BTY significantly enhanced IGFBP2 and CaMKK2 expression and trophoblast proliferation, whereas inhibitors of IGF1R/PI3K/AKT pathway or CaMKK2 blocked the effect of BTY on trophoblast proliferation. In addition, IGFBP2 siRNA suppressed BTY-induced CaMKK2 expression. Caffeic acid, as one of components of BTY, increased intracellular Ca2+ concentration and proliferation in trophoblast.

Conclusion

Our research showed that BTY may have therapeutic benefits on RM through multiple targets and pathways, such as the IGF1R/PI3K/AKT and Ca2+/calmodulin signaling pathways.

tRF-5028c disrupts trophoblast function in recurrent spontaneous abortion by inhibiting CRKL-mediated Rap1 signaling pathway

BACKGROUND

Recurrent spontaneous abortion (RSA) affects approximately 1-5% of childbearing women and poses a significant threat to global reproductive health. Transfer RNA-derived small RNAs (tsRNAs) are a novel class of noncoding RNAs implicated in various human diseases. However, the role and mechanism of tsRNAs in regulating trophoblast function during RSA development remain unknown.

METHODS

High-throughput sequencing was performed to analyze the differential tsRNAs in the villous tissues of patients with RSA and controls. CCK-8, transwell assay, and flow cytometry were performed to detect the effects of tRF-5028c on proliferation, migration, invasion, and apoptosis of human extravillous trophoblast cell line HTR-8/SVneo. The target genes of tRF-5028c were predicted via bioinformatic analysis and verified by dual luciferase reporter gene assay. Moreover, pregnant mice were injected with tRF-5028c mimics to confirm the findings in vivo.

RESULTS

A total of 1907 tsRNAs were detected, of which 298 were differentially expressed in the villous tissues. tRF-5028c was significantly upregulated in the RSA group compared with control. Functionally, tRF-5028c overexpression inhibited HTR-8/SVneo cell proliferation, migration, and invasion and promoted apoptosis, whereas tRF-5028c knockdown showed opposite effects. Mechanically, tRF-5028c suppressed CRKL expression by directly binding to its 3'-untranslated region, thus inactivating the downstream C3G/Rap1 signaling pathway. Finally, tRF-5028c mimics injection increased embryo absorption rate in mice.

CONCLUSIONS

tRF-5028c upregulation impaired trophoblast function to facilitate RSA development by directly targeting CRKL-mediated Rap1 pathway. The findings provide the first evidence of tsRNA dysregulation in RSA pathogenesis and lay a foundation for potential targeted therapies.

Cystatin C 3 (CST3) drives pathological progression in recurrent spontaneous abortion

This study aimed to investigate the role of Cystatin C (CST3) in trophoblast cell (TBC) function and its contribution in the development of recurrent spontaneous abortion (RSA). We established an inbred RSA model by crossing CBA/J and DBA/2 mice. We investigated and compared expression levels of CST3 and pathological changes in decidual tissues from these RSA and normal pregnant mice. We next isolated TBCs from RSA mice and transfected them with CST3 overexpression or silencing vectors to assess alterations in cell proliferation, invasion, apoptosis, autophagy, oxidative stress and inflammatory stress responses. Results showed that CST3 expression was significantly elevated in RSA mice compared to normal pregnant mice, accompanied by edema, degeneration of decidual cells, and structural disorganization. CST3 overexpression in TBCs led to a significant reduction in cloning and invasion abilities, increased apoptosis, shortened G0-G1 phase and enhanced autophagy. Conversely, silencing CST3 reversed these cellular activities, promoting TBC activity and reducing apoptosis. Additionally, CST3 overexpression intensified inflammatory and oxidative stress in TBCs, whereas silencing CST3 alleviated these stress responses, further supporting its role in RSA progression. In conclusion, CST3 is upregulated in RSA and contributes to its progression by inhibiting TBC activity, while accelerating apoptosis and autophagy. These findings suggest that CST3 silencing may offer a novel therapeutic strategy to improve pregnancy outcomes in RSA by restoring TBC function and reducing apoptosis and stress responses.

Endoplasmic reticulum stress and unfolded protein response play roles in recurrent pregnancy loss: A bioinformatics study

This study aims to explore whether endoplasmic reticulum stress (ERS) and unfolded protein response (UPR) processes could be potential targets for preventive, diagnostic, and therapeutic for recurrent pregnancy loss (RPL). RPL datasets GSE165004 and GSE26787 were sourced from the GEO database, and ERS- and UPR-related gene sets were obtained from the MsigDB database. After differentially expressed genes (DEGs) identification, key genes were screened from intersecting DEGs in RPL-ERS and RPL-UPR datasets. The z-score algorithm was conducted to obtain phenotype scores. Functional enrichment and machine learning analyses were performed to assess gene function and diagnostic value evaluation. Interaction networks were conducted to investigate upstream regulated relationships of the key genes. Immune infiltration and single-cell RNA sequencing (scRNA-seq) were assessed to explore ERS and UPR functions at the cellular level. Totally 25 key genes RPL-ERS DEGs and 16 key genes RPL-UPR DEGs were identified. Among them, six key genes (NFYB, EXOSC2, UBQLN2, RNF139, DERL1, and FBXO27) were validated to show consistent expression trends in both RPL datasets. Functional enrichment highlighted their involvement in the immunity of RPL. Machine learning indicated the significant diagnostic value of these validated genes for RPL, with an accuracy rate of > 80 %. scRNA-seq analysis revealed elevated ERS and UPR expressions in monocytes/macrophages in RPL samples. In conclusion, ERS and UPR processes are associated with RPL occurrences, and were mainly upregulated in monocytes/macrophages within RPL samples. ERS and UPR processes may serve as potential targets for the prevention, diagnosis, and treatment of RPL.

The role of necroptosis in pathological pregnancies: Mechanisms and therapeutic opportunities

Necroptosis, a distinctive form of programmed cell death differs mechanistically from apoptosis pyroptosis, and autophagy, is characterized by the activation of receptor-interacting protein kinases (RIPK1/RIPK3) and their downstream effector, mixed lineage kinase domain-like protein (MLKL). This programmed cell death pathway serves as a crucial mediator of inflammatory responses and has been implicated in the pathogenesis of diverse pathological conditions. Recent evidence has implicated dysregulated necroptosis in the pathogenesis of severe pregnancy complications, including preeclampsia (PE), fetal growth restriction (FGR), recurrent spontaneous abortion (RSA), and gestational diabetes mellitus (GDM). In these disorders, necroptosis promotes placental dysfunction through multiple interconnected mechanisms: amplification of pro-inflammatory cytokine cascades, aberrant immune activation, disruption of plasma membrane integrity, and subsequent tissue injury.These pregnancy-related pathologies consistently demonstrate elevated necroptotic signatures, correlating with adverse maternal-fetal outcomes. This comprehensive review synthesizes current understanding of the molecular mechanisms underlying necroptosis, with particular emphasis on its pivotal role in the etiopathogenesis of pregnancy-related disorders. Furthermore, we critically evaluate the therapeutic potential of targeting the necroptotic signaling axis, providing novel perspectives for developing targeted interventions to improve clinical outcomes in complicated pregnancies.

The Identification of FN1 as an Early Diagnostic Marker for Recurrent Abortion by Single-Exosome Profiling

Purpose

Recurrent abortion(RA) is a prevalent adverse pregnancy event. Exosomes, secreted by various body fluids, are known to play a role in disease diagnosis and serve as biomarkers through intercellular communication. This study aims to analyze single exosomes in patients with recurrent abortion to identify new biomarkers that may significantly contribute to recurrent abortion, providing new directions for its treatment.

Patients and Methods

A total of 244 serum exosomes were collected, including 216 patients with recurrent abortion of varying outcomes and 28 normal pregnancies. We performed the proximity barcoding assay (PBA) to analyze single exosome surface proteins, which allowed us to identify individual exosomes related to the development of RA as well as the major subpopulations of exosomes. After PBA treatment, samples were analyzed for single exosomes, and exosomes from each group were compared using volcano plots, dot plots, and ROC curves.

Results

By intersecting all significantly differentially expressed genes obtained from comparisons between the normal pregnancy control group and the recurrent abortion group, including the RA before abortion, RA after abortion, and RA non-pregnancy groups, we identified seven shared differential genes: FN1, APIPOQ, CDH13, DSG1, CLDN4, CD36, and ULBP3. Among these, FN1 was the most significantly differentially expressed gene in exosomes, with FN1 | log2 (fold change) |>1.5 and an AUC of 0.7414. In addition, exosome subpopulation analyses showed that cluster 11 accounted for the largest proportion of the total 16 subpopulations, and FN1 was the marker with the highest concentration of cluster 11.

Conclusion

Single-exosome profiling and exosome subpopulations of RA by PBA yielded significant differential gene FN1, which provides new possibilities for diagnostic screening of RA.

Metabonomics analysis of decidual tissue in patients with recurrent spontaneous abortion

OBJECTIVE

This study aimed to delineate the metabolic differences and identify enriched pathways in the decidual tissue of patients with recurrent spontaneous abortion (RSA) compared to normal pregnant women.

METHODS

A cohort of 25 RSA patients and 25 normal pregnant women was recruited for the study. Non-targeted metabolomic analysis of decidual tissue was conducted using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were employed to identify differential metabolites. Pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database to elucidate associated metabolic pathways. Quantitative polymerase chain reaction (qPCR) was utilized to assess the expression levels of key proteins related to these pathways, including acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), and indoleamine 2,3-dioxygenase (IDO).

RESULTS

A total of 54 metabolites were identified with significant differences between the decidual tissues of RSA patients and normal controls, corresponding to 29 significantly enriched metabolic pathways (P<0.05). The expression of ACSL4 was markedly upregulated, while the expression of GPX4 and IDO were significantly downregulated in RSA patients (P<0.05).

CONCLUSIONS

This study elucidates substantial metabolic disruptions in the decidual tissue of RSA patients, identifying 54 differential metabolites and 29 enriched pathways. The altered expression of ACSL4, GPX4, and IDO underscores their potential involvement in the pathogenesis of RSA. These findings provide critical insights into the metabolic mechanisms underlying RSA and suggest promising targets for diagnostic and therapeutic interventions.

FXYD1 was identified as a hub gene in recurrent miscarriage and involved in decidualization via regulating Na/K-ATPase activity

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Review of Immunological Evaluation of Patients with Recurrent Spontaneous Abortion (RSA)

In approximately half of the recurrent spontaneous abortion (RSA) cases, the underlying cause is unknown. However, most unexplained miscarriages are thought to be linked to immune dysfunction. This review summarizes the current evidence regarding the immunological evaluations of patients with RSA, with potential implications for clinical research. The immune system plays a crucial role in the successful outcome of pregnancy, as it tolerates the semi-allogeneic fetus while offering protection to both the mother and fetus from pathogens. The maternal-fetal interface is the place where the crosstalk between various immune cells such as macrophages, dendritic cells, natural killer (NK) cells, and T cells takes place. An adequate balance is required between these immune cells for pregnancy to progress. In RSA, a dysregulation between these immune players is witnessed. For example, in RSA, NK cells are not increased but also undergo a change in their activity, manifested as cytotoxic decidual NK. Similarly, regulatory T cells, which are crucial for fostering a tolerant immune environment, are decreased in RSA women. Similarly, imbalances between T-helper (Th1, Th2, Th17) cell subsets have been implicated in RSA. Furthermore, the imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophage phenotypes has been documented, with studies indicating a predominance of M1 macrophages in RSA patients. Targeting immune imbalances with therapies such as immunoglobulin administration, TNF inhibitors, and anticoagulants may improve pregnancy outcomes in women with RSA.

Angelica sinensis polysaccharide as potential protectants against recurrent spontaneous abortion: focus on autophagy regulation

Introduction

Recurrent spontaneous abortion (RSA) represents a significant clinical challenge, with its underlying mechanisms yet to be fully elucidated. Despite advances in understanding, the precise pathophysiology driving RSA remains unclear. Angelica sinensis, a traditional herbal remedy, is frequently used as an adjunctive treatment for miscarriage. However, it remains uncertain whether its primary active component, Angelica sinensis polysaccharide (ASP), plays a definitive role in its therapeutic effects. The specific function and mechanism of ASP in the context of RSA require further investigation.

Methods

In this study, we sought to evaluate autophagy levels at the maternal-fetal interface in RSA patients and in an RSA mouse model treated with ASP, complemented by a comprehensive metabolomic analysis. Autophagy flux in the decidua was compared between eight RSA patients and eight healthy pregnant women. Additionally, changes in autophagy flux were assessed in an RSA mouse model following ASP treatment, with embryos and placental tissues collected for subsequent metabolomic profiling.

Results

Our results revealed a significant reduction in Beclin 1 protein levels in the decidua of RSA patients compared to the normal pregnancy group. Conversely, ASP treatment in the RSA mouse model restored autophagy-related protein expression, including ATG7, ATG16L, and Beclin 1, to levels higher than those observed in the untreated RSA group. Metabolomic analyses further identified significant changes in phosphatidylethanolamine levels between ASP-treated and control groups, with differential metabolites enriched in pathways related to glycolysis/gluconeogenesis, glycerolipid metabolism, and glycine, serine, and threonine metabolism. Functional assays revealed that ASP enhances trophoblast cell proliferation, migration, and invasion.

Conclusion

In summary, our findings demonstrate diminished autophagy activity in RSA patients, while ASP appears to restore autophagy and regulate key metabolic pathways, including glycolysis/gluconeogenesis. These results provide new insights into the protective mechanisms of ASP in RSA, suggesting its potential as a therapeutic intervention for this condition.

Effect of Exogenous of Transforming Growth Factor-β1 on Pregnancy Outcome in Mice with Recurrent Pregnancy Loss by Persistent Enhancement of Placental Tissue Indoleamine 2,3-Dioxygenase Expression

BACKGROUND

The immunologic factors are the chief reason for recurrent pregnancy loss (RPL) and induction of maternal-fetal tolerance is the main treatment for this cause of RPL, but the effect of this method is uncertainly and needs multiple doses and/or interventions. The aim of this study was to investigate whether a single administration of transforming growth factor-β1 (TGF-β1) can improve the pregnancy outcomes of RPL mice and whether the improvement is cause by TGF-β1 driving the expression of immune tolerance molecule indoleamine 2,3-dioxygenase (IDO).

MATERIALS AND METHODS

In this experimental study, 40 RPL model mice were equally divided into a control group, that received 0.01 M phosphate-buffered saline (PBS), and a treatment group, that received PBS containing 2, 20, and 200 ng/ml TGF-β1 via tail vein injection. The mice were sacrificed at 13.5 days of pregnancy and the embryo resorption rate was determined. The expression of IDO, TGF-β1, and TGF-β3 were detected in the placenta using western blotting and immunohistochemistry techniques.

RESULTS

The expression of IDO was positively correlated with TGF-β1 in the placental tissue of RPL mice (r=0.591, P<0.001). In all treatment groups, the embryo resorption rates were significantly lower than the control group and the expression of IDO in the placental tissue of all treatment groups was significantly higher than the control group. The expression of TGF-β1 increased gradually from, 2, 20 to 200 ng/ml in treatment groups, and the concentration of exogenous TGF-β1 positively correlated with the expression of TGF-β1, in placental tissues in treatment groups (r=0.372, P=0.018).

CONCLUSION

Exogenous TGF-β1 improves pregnancy outcomes in RPL mice, and the possible therapeutic mechanism is that exogenous TGF-β1 induces the persistent expression of endogenous TGF-β1 and IDO due to mutually induced expression of the other. This experiment may provide a new direction and idea for the future treatment of RPL patients.

Associations of Th1, Th2, Th17, and Treg cell levels and imbalance with recurrent spontaneous abortion: A meta-analysis

OBJECTIVE

Abnormal levels and imbalances of T cell subsets are common in recurrent spontaneous abortion (RSA) patients, but most studies have small sample sizes, and comprehensive evaluations are lacking. Therefore, this meta-analysis aimed to comprehensively investigate T cell subsets and their ratios in RSA patients.

METHODS

Four databases (PubMed, EMBASE, Web of Science, and Cochrane Library databases) were searched until 10 January 2024. T helper 1 (Th1), Th2, Th1/Th2 ratio, Th17, regulatory T (Treg), Treg/Th17 ratio, and the correlation between Th17 and Treg were considered endpoint indexes.

RESULTS

Twenty-six studies involving 1143 RSA women (RSA group) and 863 healthy women (healthy control group) were included. Th1 (standardized mean difference [SMD] = 0.603%; 95% confidence intervals [CI]: 0.406%, 0.800%; p < 0.001), Th1/Th2 ratio (SMD = 0.838; 95% CI: 0.364, 1.312; p = 0.001), and Th17 (SMD = 1.047%; 95% CI: 0.734%, 1.360%; p < 0.001) increased; Th2 (SMD = -0.719%; 95% CI: -1.263%, -0.174%; p = 0.010), Treg (SMD = -1.176%; 95% CI: -1.755%, -0.596%; p < 0.001) and Treg/Th17 ratio (SMD = -0.978; 95% CI: -1.576, -0.381; p = 0.001) reduced in RSA group versus healthy control group. Th17 were inversely correlated with Treg in RSA patients (Correlation coefficient = -0.488; 95% CI: -0.726, -0.145; p = 0.019). The risk of bias was relatively low. There was no publication bias for Th1, Th2, or Th1/Th2 ratio; publication biases for other outcomes were corrected by the trim-and-fill method. Sensitivity analyses showed relatively high robustness.

CONCLUSION

Th1, Th1/Th2 ratio, and Th17 are elevated, while Th2, Treg, and Treg/Th17 ratio are reduced in RSA patients. Meanwhile, Th17 was inversely correlated with Treg in these patients.

Use of oral allylestrenol in women with recurrent spontaneous abortion: A retrospective clinical trial

Recurrent spontaneous abortion (RSA), defined as two or more clinically confirmed pregnancies that end before 20-24 weeks of gestation, encompasses both embryonic and fetal losses and is a significant clinical challenge. The aim of this study was to compare the efficacy of allylestrenol (AT) and progesterone in improving pregnancy outcomes in RSA. From June 2021 to June 2024, 480 participants were randomly assigned to an AT, Progesterone, or Control group. Key outcomes included early pregnancy rates, ongoing pregnancies with fetal heart activity, live birth rates after 24 weeks, and pregnancy loss before 24 weeks. Results indicated significantly higher pregnancy rates at 6-8 weeks in both the Allylestrenol (71.8%) and Progesterone groups (76.2%) compared to the Control group (57.5%). At 12 weeks, ongoing pregnancies with fetal heart activity were higher in the Allylestrenol (65%) and Progesterone groups (64%) versus the Control group (52.5%). Both treatment groups had higher live birth rates (60% and 60.6%) compared to the Control group (45%). Pregnancy loss before 24 weeks was lower in both treatment groups (31.8% and 33.1%) compared to the Control group (38.7%). No significant adverse reactions were observed, indicating good safety profiles for both treatments. These findings suggest that both treatments effectively improve pregnancy outcomes in cases of RSA with satisfactory safety, supporting their potential clinical use. However, further research is needed to explore their long-term effects and broader applicability in clinical settings.

MicroRNA-200c promotes trophoblast cell dysfunction via inhibition of PI3K/Akt signaling in unexplained recurrent spontaneous abortion

Dysfunction in trophoblast cells is closely associated with the development of recurrent spontaneous abortion (RSA). Previous reports have indicated that microRNA (miR)-200c was upregulated in the serum of patients who have had abortions. This study aimed to investigate the regulatory effects and mechanisms of miR-200c in trophoblast cells. The human extravillous trophoblast cell line HTR-8/SVneo was either subjected to knockdown or overexpression of miR-200c, and its levels were measured using RT-qPCR. The cell behaviors of HTR-8/SVneo were assessed using CCK-8, Transwell, wound healing assays, and flow cytometry. Western blotting was used to detect the protein levels of Ki67, Bcl-2, Bax, MMP2/9, and PI3K/Akt-related markers. The findings revealed that miR-200c levels were higher in the villous tissues of URSA patients. Depletion of miR-200c impeded HTR-8/SVneo cell apoptosis and enhanced cell migration, invasiveness, and proliferation, while overexpression of miR-200c exhibited the opposite effects. The data suggested that mechanistically, miR-200c inactivated PI3K/Akt signaling in trophoblast cells. Furthermore, rescue experiments demonstrated that blocking PI3K/Akt signaling reversed the effects of miR-200c depletion on HTR-8/SVneo cell behavior. Therefore, miR-200c depletion can potentially improve trophoblast cell function by activating PI3K/Akt signaling.

CircDDX21 alleviates trophoblast dysfunction and Treg differentiation in recurrent spontaneous abortion via miR-520a-5p/ FOXP3/PD-L1 axis

BACKGROUND

Recurrent spontaneous abortion (RSA) is a common complication during pregnancy, which is a burden to patients both physically and mentally. Circular RNAs (circRNAs) play important roles in RSA. However, the roles of circDDX21 in RSA development remain unknown.

METHODS

Decidual samples were harvested from healthy pregnant women and RSA patients. In HTR-8/SVneo and Bewo trophoblast cells, proliferation and migration were analyzed by cell counting kit-8 (CCK-8)/5-ethynyl-2'-deoxyuridine (EdU) staining and transwell/wound healing assays, respectively. CD4+ T cells from peripheral blood mononuclear cells of patients were incubated with trophoblast-conditioned medium. Regulatory T cells (Treg) proliferation was detected by carboxyfluorescein succinimidyl ester (CFSE) assay. Treg proportion, Treg/T helper 17 cells (Th17) ratio, and cytokines were measured using flow cytometry. The association among genes was validated using dual-luciferase assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP).

RESULTS

CircDDX21 and Forkhead box P3 (FOXP3) decreased, while miR-520a-5p increased in the decidual tissues of RSA patients. CircDDX21 overexpression promoted trophoblast proliferation and migration, and facilitated CD4+ T cell differentiation into Treg. CircDDX21 targeted miR-520a-5p to elevate FOXP3. MiR-520a-5p overexpression reversed the promoted trophoblast cell function of circDDX21 overexpression in HTR-8/SVneo cells. FOXP3 overexpression reversed the repressed trophoblast cell function elicited by miR-520a-5p overexpression in HTR-8/SVneo cells. FOXP3 promoted Treg differentiation by transcriptionally upregulating programmed cell death ligand 1 (PD-L1).

CONCLUSION

CircDDX21 ameliorated trophoblast dysfunction and Treg differentiation in RSA via miR-520a-5p/FOXP3/PD-L1 axis.

KLF4 regulates trophoblast function and associates with unexplained recurrent spontaneous abortion

BACKGROUND

Recurrent spontaneous abortion (RSA) is defined as two or more consecutive spontaneous abortions before 20 weeks with the same spouse [1]. However, approximately 50% of RSA cases of unknown cause are classified as unexplained recurrent spontaneous abortion (URSA). Potential factors include decreased trophoblast cell migration and invasion, leading to impaired placental implantation and maintenance of the normal maternal-fetal interface. However, the mechanism of this pathogenesis remains unknown. In this study, we investigated the potential role and mechanism of KLF4 in regulating URSA by influencing the invasion and migration ability of trophoblast cells.

METHODS

We firstly identified 817 differentially expressed genes by performing a difference analysis of the dataset GSE121950 [2] related to recurrent abortion, and intersected the top 10 genes obtained respectively by the three algorithms: DMNC, MNC, and EPC using Venn Diagram.To detect the expression levels of core genes, villi samples were obtained from normal pregnant women and patients with URSA. RT-qPCR analysis revealed a significant difference in KLF4 mRNA expression and KLF4 was then analyzed. Trophoblast cell lines HTR8 and JEG3 were used to investigate the effect of KLF4 on trophoblastic function. Wound healing and transwell assays was performed to detect the invasion and migration of trophoblast cells. The expression of epithelial-mesenchymal transition(EMT) molecules were detected by RT-qPCR and western blot. Promoter detection and epigenetic modification were detected by chromatin immunoprecipitation (ChIP) assay. Molecular nuclear localization was detected by immunofluorescence and subcellular fractionation. Miscarried mice model was used to study the effects of KLF4 on URSA induced by reduced trophoblast invasion and migration.

RESULTS

KLF4 is highly expressed in the villi of patients with URSA. KLF4 inhibits the expression level of H3R2ME2a in trophoblast cells by regulating the transcriptional level and nuclear translocation of PRMT6, thereby inhibiting the possible regulatory mechanism of trophoblastic invasion and providing a potential treatment strategy for URSA in vivo.

CONCLUSIONS

The KLF4/PRMT6/H3R2ME2a axis regulates mechanisms associated with unexplained recurrent spontaneous abortion by regulating trophoblast function.

Biomarkers and diagnostic significance of non-coding RNAs in extracellular vesicles of pathologic pregnancy

Intercellular communication is an important mechanism for the development and maintenance of normal biological processes in all organs, including the female reproductive system. Extracellular vesicles, as important carriers of intercellular communication, contain a variety of biologically active molecules, such as mRNAs, miRNAs, lncRNAs, and circRNAs, which are involved in cell-to-cell exchanges as well as in many physiological and pathological processes in the body. Compared with biomarkers found in tissues or body fluids, extracellular vesicles show better stability due to the presence of their envelope membrane which prevents the degradation of the RNA message in their vesicles. Therefore, the genomic and proteomic information contained in extracellular vesicles can serve as important markers and potential therapeutic targets for female reproductive system-related diseases or placental function. Moreover, changes in the expression of non-coding RNAs (mainly miRNAs, lncRNAs, and circRNAs) in maternal extracellular vesicles can accurately and promptly reflect the progress of female reproductive system diseases. The aim of this review is to collect information on different types of non-coding RNAs with key molecular carriers in female pathologic pregnancies (preeclampsia and recurrent spontaneous abortion), so as to explore the relevant molecular mechanisms in female pathologic pregnancies and provide a theoretical basis for clinical research on the pathogenesis and therapeutic approaches of reproductive system diseases. The current state of the art of exosome isolation and extraction is also summarized.

Study on pharmacokinetic and tissue distribution of hyperin, astragalin, kaempferol-3-O-β-D-glucuronide from rats with multiple administrations of Semen Cuscutae processed with salt solution with effect of treating recurrent spontaneous abortion

Introduction

Semen Cuscutae is a traditional Chinese medicine (TCM) that tonifies the kidneys and prevents miscarriage. According to Chinese medicine theory, kidney deficiency is one of the main causes of recurrent spontaneous abortion (RSA). The previous studies showed that raw product of Semen Cuscutae (SP) and Semen Cuscutae processed with salt solution (YP) have ameliorative effects on RSA, and that YP is superior to SP. However, the active components of YP to ameliorate RSA remain unclear and require further studies. The objective of this study is to investigate the active components of YP in ameliorating RSA.

Methods

First, a rat model of RSA was established using hydroxyurea in combination with mifepristone. Aqueous decoction of YP was given by gavage to rats. Second, pregnant rats were sampled on days 5, 7, 9, 10 and 12 during the modelling period. The content of Hyperin (HY), astragalin (AS) and kaempferol-3-O-β-D-glucuronide (KA) in blood and liver, heart, spleen, lung and kidney tissues were detected by liquid chromatography-mass spectrometry (LC-MS). The pharmacodynamic indicators including progesterone (P), chorionic gonadotropin β (β-HCG), estradiol (E2), tumor necrosis factor-α (TFN-α), interleukin 4 (IL-4), and tryptophan (TRP) were measured by enzyme-linked immunosorbent assay (ELISA) Pearson's correlation analysis and grey relational analysis were used to establish the relationship between the pharmacodynamic indexes and chemical constituents.

Results

The pharmacokinetic results showed that the area under curve (AUC) value of KA was the largest. The tissue distribution results showed that astragalin was widely distributed in liver, heart, spleen, lung and kidney in the RSA model rats, while HY was detected only in the uterus, and KA was detected only in the kidney. The pearson correlationl analysis showed that KA was significantly and positively correlated with the contents of E2, P, β-HCG and TRP. Both AS and HY were significantly negatively correlated with the content of TNF-α, respectively.

Discussion

This study reveals the pharmacokinetics and tissue distribution of KA, AS and HY in rats with RSA. It was elucidated that all three were involved in the regulation of progesterone levels and immune function. It initially revealed the mechanism of action of YP in enhancing the improvement of RSA, and it provided a theoretical basis for the quality assessment of YP.

Polycystic ovarian syndrome (PCOS) and recurrent spontaneous abortion (RSA) are associated with the PI3K-AKT pathway activation

Aims

We aimed to elucidate the mechanism leading to polycystic ovarian syndrome (PCOS) and recurrent spontaneous abortion (RSA).

Background

PCOS is an endocrine disorder. Patients with RSA also have a high incidence rate of PCOS, implying that PCOS and RSA may share the same pathological mechanism.

Objective

The single-cell RNA-seq datasets of PCOS (GSE168404 and GSE193123) and RSA GSE113790 and GSE178535) were downloaded from the Gene Expression Omnibus (GEO) database.

Methods

Datasets of PSCO and RSA patients were retrieved from the Gene Expression Omnibus (GEO) database. The "WGCNA" package was used to determine the module eigengenes associated with the PCOS and RSA phenotypes and the gene functions were analyzed using the "DAVID" database. The GSEA analysis was performed in "clusterProfiler" package, and key genes in the activated pathways were identified using the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Real-time quantitative PCR (RT-qPCR) was conducted to determine the mRNA level. Cell viability and apoptosis were measured by cell counting kit-8 (CCK-8) and flow cytometry, respectively.

Results

The modules related to PCOS and RSA were sectioned by weighted gene co-expression network analysis (WGCNA) and positive correlation modules of PCOS and RSA were all enriched in angiogenesis and Wnt pathways. The GSEA further revealed that these biological processes of angiogenesis, Wnt and regulation of cell cycle were significantly positively correlated with the PCOS and RSA phenotypes. The intersection of the positive correlation modules of PCOS and RSA contained 80 key genes, which were mainly enriched in kinase-related signal pathways and were significant high-expressed in the disease samples. Subsequently, visualization of these genes including PDGFC, GHR, PRLR and ITGA3 showed that these genes were associated with the PI3K-AKT signal pathway. Moreover, the experimental results showed that PRLR had a higher expression in KGN cells, and that knocking PRLR down suppressed cell viability and promoted apoptosis of KGN cells.

Conclusion

This study revealed the common pathological mechanisms between PCOS and RSA and explored the role of the PI3K-AKT signaling pathway in the two diseases, providing a new direction for the clinical treatment of PCOS and RSA.

New molecular mechanisms of quercetin in improving recurrent spontaneous abortion based on in-depth network pharmacology and molecular docking

Introduction

The increasing prevalence of recurrent spontaneous abortion (RSA) poses significant physical and psychological challenges for affected individuals. Quercetin, a natural plant flavonoid, shows promise in reducing miscarriage rates, yet its precise mechanism remains elusive. This study uses network pharmacology, molecular docking, and experimental validation to explore the molecular pathways through which quercetin mitigates RSA.

Methods

Quercetin-related target genes were sourced from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and RSA target genes were retrieved from the Comparative Toxicogenomics Database (CTD), with overlapping targets identified using Venn diagrams. All genes were visualized using the STRING database, and core targets were selected with Cytoscape 3.7.3. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted using the DAVID and Reactome online resources. Subsequently, HTR-8/SVneo cells were stimulated with lipopolysaccharide (LPS) and treated with varying concentrations of quercetin (1, 5, and 10 μM), then subjected to CCK-8, wound healing, transwell, and annexin V-FITC/PI apoptosis assays. Reverse-transcription quantitative PCR was used to determine the mRNA expression levels of IL-1β, TNF-α, and IL-6 in LPS-induced cells post-quercetin intervention, and western blotting was used to measure AKT1, MMP9, and caspase-3 protein levels.

Results

A total of 139 quercetin-associated target genes were identified from the TCMSP database, and 98 disease-associated target genes were obtained from the CTD, resulting in 25 shared target genes. Gene ontology enrichment highlighted the involvement of these targets in positive regulation of apoptosis, response to hypoxia, and intrinsic apoptotic signaling pathway in response to DNA damage. KEGG pathway analysis indicated enrichment in pathways related to interleukin-4 and interleukin-13 signaling, cytokine signaling in the immune system, and apoptosis. Molecular docking studies revealed robust binding of quercetin with MMP9, AKT1, IL-1β, TNF, and caspase-3. In vitro experiments demonstrated that quercetin enhanced LPS-induced cell activity, fostering proliferation, migration, and invasion, and reducing apoptosis. Moreover, quercetin reduced IL-1β, TNF-α, and IL-6 mRNA expression, increased AKT1 and MMP9 protein levels, and reduced caspase-3 expression.

Conclusion

Quercetin could mitigate the incidence of RSA by modulating inflammatory responses and apoptotic processes, through upregulation of AKT1 and MMP9, and downregulation of caspase-3, IL-1β, TNF-α, and IL-6. Quercetin opens up a new way of thinking about treating RSA.

Elucidating the role of hepatic enzymes in spontaneous abortion: a Mendelian randomization approach

Background

While the hepatic enzymes Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) are crucial for liver function, their role in Spontaneous Abortion (SA) has not been thoroughly explored. Utilizing Mendelian Randomization (MR), this study aims to clarify the putative causal relationship between AST/ALT levels and SA.

Methods

Genome-wide association study (GWAS) summary data for SA (finn-b-O15_ABORT_SPONTAN), AST (ukb-d-30650_raw), and ALT (ukb-d-30620_raw) were acquired from the Integrative Epidemiology Unit OpenGWAS database. Bidirectional MR analysis was conducted using MR-Egger, Weighted Median, Simple Mode, Weighted Mode, and Inverse Variance Weighted (IVW) algorithms, and the robustness of MR results was assessed through sensitivity analyses including Heterogeneity, Horizontal Pleiotropy, and Leave-One-Out (LOO) tests. The causal role of AST and ALT's coaction in SA was explored via multivariable MR (MVMR) analysis.

Results

The MR results via the IVW algorithm revealed a causal relation between both AST and ALT and SA (AST: P = 0.013; ALT: P = 0.017), identifying them as risk factors for SA (AST: odd ratio (OR) = 1.019; ALT: OR = 1.012). Sensitivity analysis substantiated the reliability of these results. Moreover, not notably causality was found between SA and AST/ALT (P > 0.05). Through MVMR analysis, AST and ALT demonstrated functional complementarity in the occurrence of SA, attributable to counterbalanced causalities (AST: P = 0.128; ALT: P = 0.899).

Conclusion

The study substantiates a causal linkage between transaminase levels and SA, enhancing our understanding of their biological interaction and the regulatory mechanisms at play. These insights could have implications for identifying novel biomarkers and therapeutic targets for SA.

Effect of IVIG therapy on pregnant women with unexplained recurrent spontaneous abortion: a systematic review and meta-analysis

Objective

To assess the effect of intravenous immunoglobulin (IVIG) therapy on unexplained recurrent spontaneous abortion (URSA).

Methods

We retrieved all randomized controlled trials (RCTs) related to the effect of IVIG therapy on URSA in the following databases: PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials before April 30, 2023, according to the PRISMA statement. The therapeutic effect of IVIG was measured by live birth rates. Quality assessment was conducted independently by two reviewers, based on the Newcastle-Ottawa scale. For the meta-analysis, we used odds ratios (random effects model and fixed effects model). The between-study heterogeneity was assessed by the Q test. Publication bias was assessed by funnel plots.

Results

A total of 12 studies with 751 participants were included in this meta-analysis. There was no statistical significance [OR = 1.07, 95%CI (0.65, 1.75), P=0.80] between the IVIG group and the non-IVIG group, including low molecular weight heparin (LMWH) plus low-dose aspirin (LDA), intralipid, multivitamins, albumin, and normal saline. A subgroup analysis was conducted according to the different treatment regimens of the non-IVIG group. Compared to the placebo group, including multivitamins, albumin, and saline, the live birth rate of the IVIG group is superior, but there was no statistical significance [OR =1.43, 95%CI (0.99, 2.07), P=0.05]. Another subgroup analysis was performed according to URSA with positive for antiphospholipid antibodies (aPLs). Results showed the live birth rate of IVIG on URSA with positive for aPLs is inferior to that of LMWH plus LDA [OR = 0.25, 95%CI (0.11, 0.55), P=0.0007].

Conclusions

IVIG didn't increase the live birth rate of URSA compared to placebo. Conversely, compared with the IVIG, the LMWH plus LDA treatment schedule can increase the live birth rate of URSA with positive for aPLs.

Primary cilia abnormalities participate in the occurrence of spontaneous abortion through TGF-β/SMAD2/3 signaling pathway

Spontaneous abortion is the most common complication in early pregnancy, the exact etiology of most cases cannot be determined. Emerging studies suggest that mutations in ciliary genes may be associated with progression of pregnancy loss. However, the involvement of primary cilia on spontaneous abortion and the underlying molecular mechanisms remains poorly understood. We observed the number and length of primary cilia were significantly decreased in decidua of spontaneous abortion in human and lipopolysaccharide (LPS)-induced abortion mice model, accompanied with increased expression of proinflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. The length of primary cilia in human endometrial stromal cell (hESC) was significantly shortened after TNF-α treatment. Knocking down intraflagellar transport 88 (IFT88), involved in cilia formation and maintenance, promoted the expression of TNF-α. There was a reverse regulatory relationship between cilia shortening and TNF-α expression. Further research found that shortened cilia impair decidualization in hESC through transforming growth factor (TGF)-β/SMAD2/3 signaling. Primary cilia were impaired in decidua tissue of spontaneous abortion, which might be mainly caused by inflammatory injury. Primary cilia abnormalities resulted in dysregulation of TGF-β/SMAD2/3 signaling transduction and decidualization impairment, which led to spontaneous abortion.

The mechanism of Shoutai Wan in the treatment of recurrent spontaneous abortion - A review

Recurrent spontaneous abortion (RSA) is a prevalent pregnancy complication with a complex and poorly understood pathogenesis. Shoutai Wan (STW), a traditional Chinese medicine formula, is renowned for its kidney tonifying and fetus tranquilizing effects. It is used to treat miscarriages associated with kidney deficiency, hyperemesis gravidarum, and fetal restlessness. Recently, there has been an increase in experimental studies exploring the use of STW for RSA treatment, making progress in understanding its molecular mechanisms and signaling pathways. This review aims to systematically elucidate the mechanisms by which STW enhances cellular antioxidant capacity, attenuates inflammation, and improves the environment for embryo implantation. This involves regulating multiple signaling pathways, including Nuclear factor-erythroid 2-related factor 2/Heme oxygenase-1, JAK kinase 1/Signal transducer and activator of transcription 3, NOD-like receptor pyrin domain-containing protein/Caspase-1/Gasdermin D, Human Leukocyte Antigen G, Mitogen-activated protein kinase, and Serum and glucocorticoid-regulated kinase 1/Epithelial sodium channel. This review provides a theoretical reference for the clinical application and further experimental researches on the treatment of RSA with STW.

Role of maternal-fetal immune tolerance in the establishment and maintenance of pregnancy

ABSTRACT

Normal pregnancy is a contradictory and complicated physiological process. Although the fetus carries the human leukocyte antigen (HLA) inherited from the paternal line, it does not cause maternal immune rejection. As the only exception to immunological principles, maternal-fetal immune tolerance has been a reproductive immunology focus. In early pregnancy, fetal extravillous trophoblast cells (EVTs) invade decidual tissues and come into direct contact with maternal decidual immune cells (DICs) and decidual stromal cells (DSCs) to establish a sophisticated maternal-fetal crosstalk. This study reviews previous research results and focuses on the establishment and maintenance mechanism of maternal-fetal tolerance based on maternal-fetal crosstalk. Insights into maternal-fetal tolerance will not only improve understanding of normal pregnancy but will also contribute to novel therapeutic strategies for recurrent spontaneous abortion, pre-eclampsia, and premature birth.

ANXA5 and VEGFA Gene Variants in Women with Early Pregnancy Losses from North Macedonia

Early pregnancy loss (EPL) is the most common pregnancy complication, found in approximately 15% of all clinically recognized pregnancy complications. Up to date, various maternal as well as fetal factors are reported as a cause of EPLs. However, in approximately 50% of EPL cases, the exact cause is not clearly identified and these cases are referred as idiopathic. The aim of our study was to examine the association of four distinct variants in the ANXA5 gene and two variants within the VEGFA gene in a cohort of women with EPLs from North Macedonia. This group was compared to a control group of women matched by ethnic background without pregnancy loss and at least one live birth. We also aimed to establish an effective and cost-efficient method for their detection based on multiplex single-base extension. Among 190 women experiencing EPLs, and 190 samples from women without a history of pregnancy loss (control group), our results demonstrated a statistically significant prevalence of heterozygotes for the M2/ANXA5 haplotype in women with EPLs, compared to the control group (p=0.0006). In the analyses comparing genotypic frequencies for the variants in the VEGFA gene, higher frequencies were generally observed among women experiencing EPLs, however without statistical significance. Our study aligns with multiple studies showing that M2 and M1 ANXA5 haplotypes are more prevalent in patients with pregnancy loss and presents an affordable genotyping technique for the specific ANXA5 and VEGFA variants.

A preliminary study unveils CISD2 as a ferroptosis-related therapeutic target for recurrent spontaneous abortion through immunological analysis and two-sample mendelian randomization

Recurrent spontaneous abortion (RSA) affects approximately 1 % of women striving for conception, posing a significant clinical challenge. This study aimed to identify a prognostic signature in RSA and elucidate its molecular mechanisms. Prognostic gene impacts were further assessed in HTR-8/SVneo and human primary extravillous trophoblast (EVT) cells in vitro experiments. A total of 6168 differentially expressed genes (DEGs) were identified, including 3035 upregulated and 3133 downregulated genes. WGCNA pinpointed 8 significant modules and 31 ferroptosis-related DEGs in RSA. Optimal clustering classified RSA patients into three distinct subgroups, showing notable differences in immune cell composition. Six feature genes (AEBP2, CISD2, PML, RGS4, SRSF9, STK11) were identified. The diagnostic model showed high predictive capabilities (AUC: 0.966). Mendelian randomization indicated a significant association between CISD2 levels and RSA (OR: 1.069, P-value: 0.049). Furthermore, the downregulation of CISD2 promotes ferroptosis in HTR-8/SVneo and human primary EVT cells. CISD2 emerged as a pivotal gene in RSA, serving as a ferroptosis-related therapeutic target. The diagnostic model based on gene expression and Mendelian randomization provides novel insights into the pathogenesis of RSA.

Causal Relationship Between Circulating Immune Cells and Recurrent Spontaneous Abortion: A Bidirectional Mendelian Randomization Study

BACKGROUND

Recurrent spontaneous abortion (RSA) is a serious and common complication of pregnancy caused by multiple factors. The etiology remains incompletely understood, but immunologic factors play important roles. Here, we aimed to evaluate whether circulating immune cells causally impacted RSA.

METHODS

In this study, we conducted a comprehensive two-sample Mendelian randomization (MR) study to determine the causal association between the 731 immunophenotypes of human peripheral blood lymphocytes and the number of spontaneous abortions as well as recurrent miscarriage. Sensitivity analyses were performed to assess and minimize heterogeneity and horizontal pleiotropy. Reverse MR analysis was used to assess reverse causality.

RESULTS

After Bonferroni-correction, eight immunophenotypes were significantly associated with the number of spontaneous abortions: FSC-A on CD4+ T cell (beta = -0.051, 95% CI = [-0.085, -0.017], P-value = 0.004), CD8 on HLA DR+ CD8+ T cell (beta = -0.040, 95% CI = [-0.067, -0.014], P-value = 0.003), HLA DR on CD33dim HLA DR+ CD11b- (beta = -0.021, 95% CI = [-0.036, -0.005], P-value = 0.010), HLA DR+ T cell Absolute Count (beta = 0.022, 95% CI = [0.006, 0.037], P-value = 0.008), HLA DR+ T cell % lymphocyte (beta = 0.026, 95% CI = [0.010, 0.041], P-value = 0.001), HLA DR+ T cell % T cell (beta = 0.023, 95% CI = [0.007, 0.039], P-value = 0.004), HLA DR+ CD4+ T cell % lymphocyte (beta = 0.034, 95% CI = [0.007, 0.060], P-value = 0.012), and HLA DR on B cell (beta = 0.012, 95% CI = [0.003, 0.021], P-value = 0.010). In addition, we identified two immunophenotypes associated with recurrent miscarriage: HLA DR on B cell (OR = 0.854, 95% CI = [0.757, 0.964], P-value = 0.011), and CD19 on naive-mature B cell (OR = 4.595, 95% CI = [1.674, 12.617], P-value = 0.003). There was no evidence of heterogeneity, horizontal pleiotropy and reverse causality.

CONCLUSIONS

Our study demonstrated a tight link between adaptive immune cells and RSA through genetic means, thus providing potential therapeutic targets or novel diagnostic biomarkers.

Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function

INTRODUCTION

Spontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage.

METHODS

Placental villi (7-10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2'-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse).

RESULTS

In placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing.

DISCUSSION

Low expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

Maternal-fetal immunity and recurrent spontaneous abortion

Recurrent Spontaneous Abortion (RSA) is a common pregnancy complication, that has multifactorial causes, and currently, 40%-50% of cases remain unexplained, referred to as Unexplained RSA (URSA). Due to the elusive etiology and mechanisms, clinical management is exceedingly challenging. In recent years, with the progress in reproductive immunology, a growing body of evidence suggests a relationship between URSA and maternal-fetal immunology, offering hope for the development of tailored treatment strategies. This article provides an immunological perspective on the pathogenesis, diagnosis, and treatment of RSA. On one hand, it comprehensively reviews the immunological mechanisms underlying RSA, including abnormalities in maternal-fetal interface immune tolerance, maternal-fetal interface immune cell function, gut microbiota-mediated immune dysregulation, and vaginal microbiota-mediated immune anomalies. On the other hand, it presents the diagnosis and existing treatment modalities for RSA. This article offers a clear knowledge framework for understanding RSA from an immunological standpoint. In conclusion, while the "layers of the veil" regarding immunological factors in RSA are gradually being unveiled, our current research may only scratch the surface. In terms of immunological etiology, effective diagnostic tools for RSA are currently lacking, and the efficacy and safety of immunotherapies, primarily based on lymphocyte immunotherapy and intravenous immunoglobulin, remain contentious.

GRIM-19 deficiency promotes macrophage polarization to the M1 phenotype partly through glycolysis in unexplained recurrent spontaneous abortion†

The occurrence of unexplained recurrent spontaneous abortion (URSA) is closely related to immune system disorders, however, the underlying mechanisms remain unclear. The purpose of this study was to investigate the expression of GRIM-19 in URSA and the possible pathogenesis of URSA according to macrophage polarization. Here, we showed that GRIM-19 was downregulated in the uterine decidual macrophages of patients with URSA and that GRIM-19 downregulation was accompanied by increased M1 macrophage polarization. Furthermore, the expression levels of glycolytic enzymes were substantially enhanced in the uterine decidual macrophages of URSA patients, and glycolysis in THP-1-derived macrophages was further enhanced by the downregulation of GRIM-19. Additionally, the increase of M1 macrophages resulting from the loss of GRIM-19 was significantly reversed in cells treated with 2-deoxy-D-glucose (2-DG, an inhibitor of glycolysis). To provide more direct evidence, GRIM-19 deficiency was shown to promote macrophage polarization to the M1 phenotype in GRIM-19+/- mouse uteri. Overall, our study provides evidence that GRIM-19 deficiency may play a role in regulating macrophage polarization in URSA, and that glycolysis may participate in this process.

Impact of Sjögren's syndrome on maternal and fetal outcomes following pregnancy: a systematic review and meta-analysis of studies published between years 2007-2022

OBJECTIVE

To show the impact of Sjögren's syndrome (SS) on maternal and fetal outcomes following pregnancy.

METHODS

We performed a literature search based on PubMed, Web of science, Wan fang, China National Knowledge Infrastructure and ProQuest databases from 1 January 2007 to 6 November 2022. Grading of Recommendations, Assessment, Development, and Evaluations approach was used to assess the certainty of the evidence. Systematic reviews and meta-analyses were performed using RevMan 5.3 software. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird. Trial sequential analyses were performed by TSA 0.9.

RESULTS

Nine studies with 2341 patients and 2472 pregnancies with SS were included in our analysis. This current analysis showed pregnancy hypertension and preeclampsia/eclampsia to be significantly higher in pregnant women with SS compared to pregnant women without SS (OR: 1.65, 95% CI: 1.04-2.63; P = 0.03), (OR: 2.06, 95% CI: 1.16-3.65; P = 0.01) respectively. Cesarean section, thromboembolic disease, premature rupture of membranes, and spontaneous abortion were also significantly higher in the SS women with OR: 2.07, 95% CI: 1.48-2.88; P < 0.0001, OR: 9.45, 95% CI: 1.99-44.87; P = 0.005, OR: 1.36, 95% CI: 1.13-1.64; P = 0.001, OR: 9.30, 95% CI: 4.13-20.93; P < 0.00001, respectively. Significantly higher premature births were observed with infants who were born from SS mothers (OR: 2.19, 95% CI: 1.54-3.12; P < 0.0001). Infants defined as 'small for gestational age/intrauterine growth restriction' and 'weighing < 2500 g' were also significantly higher in patients suffering from SS (OR: 2.26, 95% CI: 1.38-3.70; P = 0.001), (OR: 3.84, 95% CI: 1.39-10.61; P = 0.009) respectively. In addition, live birth significantly favored infants who were born from mothers without SS (OR: 21.53, 95% CI: 8.36-55.44; P < 0.00001). Subgroup analysis by sample size revealed that pregnancy hypertension risk has significantly increased in small cohort (OR: 2.74, 95%CI: 1.45-5.18), and a slight increase was found in population-based studies (OR: 1.14, 95%CI: 0.91-1.43). In both small cohorts and population-based researches, cesarean section was significantly higher in SS (OR: 2.13, 95% CI: 1.29, 3.52; OR: 1.85, 95% CI: 1.29-2.64, respectively). The number of infants with intrauterine growth restriction did not grow in the population-based researches (OR: 2.07, 95%CI: 0.92-4.66) although there has been an increase in small reports (OR: 2.53, 95%CI: 1.16-5.51). Subgroup analysis was conducted on the basis of study location (not Asian vs. Asian countries) indicated that cesarean section was significantly higher in SS in both countries (OR: 1.69, 95% CI: 1.31-2.18; OR: 3.37, 95% CI: 2.39-4.77, respectively).

CONCLUSION

This meta-analysis has shown SS to have a high impact on maternal and fetal outcomes following pregnancy.

Overexpression of regulatory T cells in patients with unexplained recurrent pregnancy loss: friend or foe?

Background

This study aimed to investigate the role of regulatory T cells in patients with unexplained recurrent pregnancy loss (URPL).

Methods

We retrospectively analyzed 136 women who had experienced two or more miscarriages before 24 weeks of gestation for no obvious reason from May 2018 to October 2021. The basic clinical data of the patients and expression of lymphocyte subsets such as regulatory T cells (Tregs) and natural killer cells (NKs) by flow cytometry were collected to explore the risk factors of pregnancy outcome in URPL patients.

Results

A total of 136 URPL patients were enrolled in this study. Eventually, 50 patients attained clinical pregnancy. The median age was 31.8 ± 4.6 years in patients with clinical pregnancy. The univariate and multivariate logistic regression analyses indicated that Tregs was associated with the pregnancy outcomes of patients with URPL (odds ratio 0.63, 95% confidence interval 0.50-0.80). More importantly, a U-shaped association was found between Tregs and pregnancy outcome (p < 0.001), with either higher or lower Tregs levels adversely affecting pregnancy outcome.

Conclusion

Tregs levels that are either too high or too low can harm pregnancy outcomes. It was expected to be a very promising quantitative biomarker for predicting pregnancy outcomes in URPL patients.

Molecular Determinants of Uterine Receptivity: Comparison of Successful Implantation, Recurrent Miscarriage, and Recurrent Implantation Failure

Embryo implantation is one of the most remarkable phenomena in human reproduction and is not yet fully understood. Proper endometrial function as well as a dynamic interaction between the endometrium itself and the blastocyst-the so-called embryo-maternal dialog-are necessary for successful implantation. Several physiological and molecular processes are involved in the success of implantation. This review describes estrogen, progesterone and their receptors, as well as the role of the cytokines interleukin (IL)-6, IL-8, leukemia inhibitory factor (LIF), IL-11, IL-1, and the glycoprotein glycodelin in successful implantation, in cases of recurrent implantation failure (RIF) and in cases of recurrent pregnancy loss (RPL). Are there differences at the molecular level underlying RIF or RPL? Since implantation has already taken place in the case of RPL, it is conceivable that different molecular biological baseline situations underlie the respective problems.

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

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

Recognition of the Subtypes Classification and Diagnostic Signature Based on RNA N6-Methyladenosine Regulators in Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is a common reproductive disease in female patients that seriously affects the quality of life of patients. N6-methyladenosine (m6A), as the most common modification, plays an important role in various biological behaviors; however, the relationship between m6A and RSA is still unknown. In the present study, we utilized RNA sequencing data and clinical information of RSA patients and normal women in the GEO database to identify the expression profiles of m6A regulators in RSA. Based on the m6A regulators' expression profiles, we constructed a random forest model consisting of 4 genes to predict the prevalence of RSA patients, including FMR1, METTL14, LRPPRC, and RBMX. The predictive performance of the nomogram was constructed and validated. Not only that, consensus clustering was performed to divide RSA patients into 3 clusters based on the expression of m6A regulators and calculated the m6A scores and immune infiltration of patients in different clusters. It was found that the TH1-type immune response was dominant in the A cluster, the B-type immune activity was poor, and the C cluster was the strongest. In addition, on the basis of m6A typing, we further used the differentially expressed genes between clusters to perform consensus clustering verification, and the results were consistent with the previous findings. In conclusion, the m6A regulators played an indispensable role in the occurrence of RSA, and the m6A-based typing could effectively identify the immune characteristics of different RSA patients to a certain extent, providing a new direction and strategy for the diagnosis and treatment of RSA patients.

Non-coding RNA profile for natural killer cell activity

Natural killer cells (NK cells) are a type of cytotoxic lymphocytes which are involved in innate immunity, alongside with assisting with adaptive immune response. Since they have cytotoxic effects, disruptions in their functionality and development leads to a variety of conditions, whether malignant or non-malignant. The profile and interaction of these non-coding RNAs and NK cells in different conditions is extensively studied, and it is now approved that if dysregulated, non-coding RNAs have detrimental effects on NK cell activity and can contribute to the pathogenesis of diverse disorders. In this review, we aim at a thorough inspection on the role of different non-coding RNAs on the activity and development of NK cells, in a broad spectrum of conditions, including blood-related disorders, viral infections, neurological diseases, gastrointestinal disorders, lung disorders, reproductive system conditions and other types of maladies, alongside with providing insight to the future non-coding RNA-NK cell studies.

Role of the CD40-CD40L expression level pathway in the diagnosis of unexplained recurrent pregnancy loss

BACKGROUND

Unexplained recurrent spontaneous pregnancy loss (URPL) lacks effective treatment and reliable early diagnosis and prediction. Immunologic dysfunction can be an underlying cause of recurrent pregnancy loss (RPL). Considering the regulatory role of CD40-CD40L in immune responses, we explored its clinical significance in URPL.

METHODS

The 108 women with URPL who were treated in Hebei Yanda Hospital from January 2020 to December 2022 were selected as study subjects, and another 108 healthy women who were not pregnant and matched with the age and body mass index of the study group were selected as the control group. CD40 and CD4 + CD25 + Treg cells in peripheral blood mononuclear cells (PBMCs) and CD40L in peripheral blood platelets were measured by flow cytometry. The predictive value of CD40-CD40L in URPL for the risk of RPL was determined by receiver operating characteristic (ROC) curves. The correlations of CD40-CD40L with CD4 + CD25 + Treg cells and serum pro-inflammatory factors were assessed by Pearson's analysis.

RESULTS

CD40 on the surface of PBMCs and CD40L on the surface of platelets were up-regulated in URPL patients. CD40 in combination with CD40L had high predictive value for the risk of RPL in URPL patients. Peripheral blood CD40-CD40L was positively linked to IL-17 and IL-23, and negatively to CD4 + CD25 + Treg cells and IL-10 in URPL patients.

CONCLUSIONS

The CD40-CD40L pathway expression in peripheral blood can help predict the risk of RPL in URPL patients.

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.

Aquaporin 9 causes recurrent spontaneous abortion by inhibiting trophoblast cell epithelial-mesenchymal transformation and invasion through the PI3K/AKT pathway†

BACKGROUND

Invasion of the endometrium by trophoblast cells is a key event during pregnancy, although the underlying mechanism remains unclear. Aquaporin 9 (AQP 9) is expressed in many eukaryotes and is associated with cell invasion. The objective of this study was to evaluate the significance of AQP9 in recurrent spontaneous abortion.

METHODS

We screened the GSE22490 dataset and further differentiated aquaporin 9 expression in villi. AQP9 was evaluated as one of the key factors in abortion by injecting AQP9 overexpressed plasmid into the uterus of CD1 mice. Trophoblast cells were transfected with AQP9-overexpressing plasmid or siAQP9 to measure cell proliferation, migration, invasion, and apoptosis. Western blot was used to measure changes in the expression of invasion, epithelial-mesenchymal transformation process, and PI3K/AKT pathway. Finally, the role of AQP9 in PI3K/AKT signaling pathway was determined using the PI3K/AKT inhibitor, LY294002, and activator, 740Y-P.

RESULTS

AQP9 is highly expressed in recurrent spontaneous abortion villus. Intrauterine injections of AQP9-overexpressing plasmid into CD1 mice resulted in atrophy and blackness of the gestational sac and increased the absorption rate, it is the causative factor of abortion. AQP9 upregulation inhibited the proliferation, invasion, migration, and epithelial-mesenchymal transformation process in vitro of trophoblast cells and increased cell apoptosis. The opposite result was observed after silencing AQP9. AQP9 overexpression also inhibited the PI3K/AKT pathway. LY294002 and 740Y-P partially recovered AQP9-induced trophoblast invasion and migration via the PI3K/AKT pathway.

CONCLUSIONS

AQP9 reduces the invasive ability of trophoblast cells by regulating PI3K/AKT signaling pathway, participating in recurrent spontaneous abortion.

Biogenesis and function of exosome lncRNAs and their role in female pathological pregnancy

Preeclampsia, gestational diabetes mellitus, and recurrent spontaneous abortion are common maternal pregnancy complications that seriously endanger women's lives and health, and their occurrence is increasing year after year with a rejuvenation trend. In contrast to biomarkers found freely in tissues or body fluids, exosomes exist in a relatively independent environment and provide a higher level of stability. As backbone molecules, guidance molecules, and signaling molecules in the nucleus, lncRNAs can regulate gene expression. In the cytoplasm, lncRNAs can influence gene expression levels by modifying mRNA stability, acting as competitive endogenous RNAs to bind miRNAs, and so on. Exosomal lncRNAs can exist indefinitely and are important in intercellular communication and signal transduction. Changes in maternal serum exosome lncRNA expression can accurately and timely reflect the progression and regression of pregnancy-related diseases. The purpose of this paper is to provide a reference for clinical research on the pathogenesis, diagnosis, and treatment methods of pregnancy-related diseases by reviewing the role of exosome lncRNAs in female pathological pregnancy and related molecular mechanisms.

Omega-3 fatty acid supplements and recurrent miscarriage: A perspective on potential mechanisms and clinical evidence

Recurrent miscarriage (RM) affects approximately 1%-5% of couples worldwide. Due to its complicated etiologies, the treatments for RM also vary greatly, including surgery for anatomic factors such as septate uterus and uterine adhesions, thyroid modulation drugs for hyperthyroidism and hypothyroidism, and aspirin and low molecular weight heparin for antiphospholipid syndrome. However, these treatment modalities are still insufficient to solve RM. Omega-3 fatty acids are reported to modulate the dysregulation of immune cells, oxidative stress, endocrine disorders, inflammation, etc., which are closely associated with the pathogenesis of RM. However, there is a lack of a systematic description of the involvement of omega-3 fatty acids in treating RM, and the underlying mechanisms are also not clear. In this review, we sought to determine the potential mechanisms that are highly associated with the pathogenesis of RM and the regulation of omega-3 fatty acids on these mechanisms. In addition, we also highlighted the direct and indirect clinical evidence of omega-3 fatty acid supplements to treat RM, which might encourage the application of omega-3 fatty acids to treat RM, thus improving pregnancy outcomes.

Treatment of recurrent pregnancy loss in women with euthyroid-based thyroid peroxidase antibody syndrome

Recurrent pregnancy loss (RPL) due to thyroid peroxidase antibody (TPOAb) syndrome remains a significant challenge in pregnancy. The current study offers better insights into miscarriages that occur due to the presence of TPOAb with euthyroid in pregnant women with a history of RPL. Out of the 347 women confirmed with unexplained RPL, only 70 (20.2%) tested positive for TPOAb (215±53). After eight women were excluded from the study due to failure to follow up, 62 participants (age range: 33±4.8 years; body mass index (BMI):25-30kg/m2 (58%) and >30kg/m2 (42%)) were included. The TPOAb-dependent RPL patients were divided according to their RPL types into 23 (30.7%) nulliparous (1˚) and 39 (69.3%) multiparous (2˚) patients, respectively. Out of the sample, 69.2% and 30.8% had a history of miscarriages during the 1st and 2nd trimesters, respectively. For treatment purposes, while screening for the TPOAb, the women received 50µg/day of L-thyroxine (LTx) for three months prior to pregnancy and during the first three months of pregnancy and were followed up until giving birth or miscarriage. Thyroxine treatment was correlated to successful normal births in 56.6% and 21.2% of pregnant women after 36 and during 28-36 weeks of gestation, respectively. However, miscarriages occurred in 18.1% and 4.1% of patients during 14-28 weeks and before 14 weeks of gestation, respectively. The current findings show the promising use of thyroxine in the control of RPL caused by euthyroid-based thyroid peroxidase antibody syndrome. This treatment has led to a significant number of women experiencing successful full-term pregnancies and giving birth to healthy babies.

Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

Recurrent pregnancy loss is a complex health challenge with no universally accepted definition. Inconsistency in definitions involves not only the number of spontaneous abortions (two or three) that are accepted for recurrent pregnancy loss but the types of pregnancy and gestational age at miscarriage. Due to the heterogeneity of definitions and criteria applied by international guidelines for recurrent pregnancy loss, the true incidence of recurrent miscarriage, which is reported to range from 1% to 5%, is difficult to estimate. Moreover, the exact etiology of recurrent pregnancy loss remains questionable; thus, it is considered a polyetiological and multifactorial condition with many modifiable and non-modifiable factors involved. Even after thoroughly evaluating recurrent pregnancy loss etiology and risk factors, up to 75% of cases remain unexplained. This review aimed to summarize and critically analyze accumulated knowledge on the etiology, risk factors, relevant diagnostic options, and management approach to recurrent pregnancy loss. The relevance of various factors and their proposed roles in recurrent pregnancy loss pathogenesis remains a matter of discussion. The diagnostic approach and the management largely depend on the etiology and risk factors taken into consideration by a healthcare professional as a cause of recurrent miscarriage for a particular woman or couple. Underestimation of social and health consequences of recurrent pregnancy loss leads to compromised reproductive health and psychological well-being of women after miscarriage. Studies on etiology and risk factors for recurrent pregnancy loss, especially idiopathic, should be continued. The existing international guidelines require updates to assist clinical practice.

Recurrent miscarriage associated with rare anti-PP1Pk antibody: a case series and literature review.. [DOI: 10.21203/rs.3.rs-2728370/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: The anti-PP1Pk antibody is a rare antibody associated with recurrent spontaneous abortion (RSA) in the first trimester. As it is a rare entity, few reports have been published, especially in China. Currently, there is no specific treatment for RSA associated with anti-PP1Pk antibody because it is a naturally occurring antibody. This study aims to report three cases of RSA associated with the anti-PP1Pk antibody to share our experiences with its management. Methods: The three patients' medical information was obtained from the medical records. Intravenous immunoglobulin and/or plasmapheresis was offered to the patients. We also made an extension research of the related literature about RSA associated with anti-PP1Pk antibody. Results: Although patients received intervention, the maternal anti-PP1Pk antibody titer remained stable and did not decrease. There were no live births. We summarized publications about pregnancy in women with anti-PP1Pk antibodies. Conclusions: Early initiation of plasmapheresis in high-risk patients with anti-PP1Pk antibodies should be strongly considered.

Efficacy and safety of recombinant human granulocyte colony-stimulating factor in patients with unexplained recurrent spontaneous abortion: A systematic review and meta-analysis

INTRODUCTION

Published data regarding efficacy of intrauterine perfusion of recombinant human granulocyte colony-stimulating factor for patients with unexplained recurrent spontaneous abortion (URSA) is inconclusive. This study aims at evaluating the efficacy and safety of G-CSF in URSA.

MATERIALS AND METHODS

Electronic databases were searched including Cochrane Library, PubMed, Embase, China Biology Medicine disc, China Science and Technology Journal Database, Wanfang Database and China National Knowledge Infrastructure Database (last search was performed on Sep 10th, 2022). A systematic review and meta-analysis was conducted with R-language software. Combined relative risk (RRs), and 95% confidence intervals (CIs) were calculated to estimate efficacy and safety.

RESULTS

Compared with placebo, the efficacy of G-CSF in the treatment of URSA patients was significant in conception rate (RR=1.34, 95%CI: 1.03-1.74, P = 0.028), and was none of significance in live birth rate (RR=1.35, 95%CI: 0.99-1.84, P = 0.06). Subgroup analysis showed that the ovulation-period-medication was the protective factor for conception rate, while "Ethnicity Asian" and "ovulation-period medication" were the protective factors for live birth rate. When it comes to the safety of rhG-CSF on URSA, meta-analysis showed that rhG-CSF had no significant effect on the incidence of adverse events (AEs) (RR=1.13, 95% CI: 0.89-1.43, P = 0.322), and subgroup analysis showed that the incidence of AEs in each subgroup did not increase significantly (P > 0.05).

CONCLUSION

Based on our meta-analysis, intrauterine perfusion of rhG-CSF in ovulation period is an effective and safe way to improve conception rate in URSA.

Potential Therapeutic Effects of Human Amniotic Epithelial Cells on Gynecological Disorders Leading to Infertility or Abortion

The induction of feto-maternal tolerance, fetal non-immunogenicity, and the regulation of mother's immune system are essential variables in a successful pregnancy. Fetal membranes have been used as a source of stem cells and biological components in recent decades. Human amniotic epithelial cells (hAEC) have stem/progenitor characteristics like those found in the amniotic membrane. Based on their immunomodulatory capabilities, recent studies have focused on the experimental and therapeutic applications of hAECs in allograft transplantation, autoimmune disorders, and gynecological problems such as recurrent spontaneous abortion (RSA), recurrent implantation failure (RIF), and premature ovarian failure (POF). This review discusses some of the immunomodulatory features and therapeutic potential of hAECs in preventing infertility, miscarriage, and implantation failure by controlling the maternal immune system.

Hyperin promotes proliferation, migration, and invasion of HTR-8/SVneo trophoblast cells via activation of JAK1/STAT3 pathway in recurrent spontaneous abortions

The proliferation of extravillous trophoblasts (EVT) and their further migration, invasion, and differentiation into the decidual and myometrial vasculature are vital for spiral artery remodeling. These physiological functions of EVT are also essential steps in the implantation of the human embryo and the formation of the placenta and are closely related to pregnancy maintenance and the occurrence of abortion. Hyperin is a flavonoid with anti-inflammatory, pro-proliferative, and anti-apoptotic properties. Consequently, we investigated the previously unexplored effects of hyperin on the proliferation, migration, and invasion of HTR-8/SVneo cells. Human extravillous trophoblast-derived HTR-8/SVneo cells were incubated with different concentrations of hyperin (0, 5, 10, 25, 50, and 100 μM) to observe the changes in cell proliferation, migration, invasive capacity, and pathway activation. Proliferation, migration, and invasion were promoted by activating the JAK1/STAT3 pathway in HTR-8/SVneo cells treated with hyperin. In addition, brepocitinib (PF-06700841) significantly inhibited the proliferation, migration, and invasion effects of hyperin on HTR-8/SVneo cells. In vivo experiments confirmed that hyperin reduces the embryo loss rate in recurrent spontaneous abortion (RSA) model mice. Furthermore, our study revealed that hyperin promoted the proliferation, migration, and invasion of HTR-8/SVneo cells via activation of the JAK1/STAT3 pathway, further improving pregnancy outcomes in RSA.