Pathogenesis Of Unexplained Recurrent Spontaneous Abortion Research Articles

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.

Bioinformatics analysis of competing endogenous RNA network in decidual natural killer cell from unexplained recurrent spontaneous abortion.

Decidual natural killer (dNK) cell plays a pivotal role in maintaining pregnancy, especially in the first trimester. Noncoding-RNAs (ncRNAs) are critical regulators of transcription and protein expression. Dysregulation of ncRNAs may be involved in the pathogenesis of unexplained recurrent spontaneous abortion (URSA). However, the role of competing endogenous RNA (ceRNA) based on mRNA-miRNA-lncRNA network in regulating the incidence and progression of URSA remains elusive. The aim of the study is to identify the regulatory network of mRNA-miRNA-LncRNA ceRNA based on bioinformatics analysis in dNK from patients with URSA. Eligible studies were retrieved from PubMed, Embase, and the Gene Expression Omnibus (GEO) databases to identify differentially expressed genes (DEGs), miRNAs and LncRNAs in dNK cells of patients with URSA. Protein-protein interaction (PPI) network was constructed by STRING database and Cytoscape software. Potential regulatory miRNAs and lncRNAs of mRNAs were predicted by miRTarBase and RNA22 and subject to bioinformatics analysis. A total of 634 DEGs were screened, including 290 upregulated and 344 downregulated DEGs. Among 207 differentially expressed lncRNAs, 110 lncRNAs were upregulated and 97 were downregulated. According to node degree, 30 hub genes were identified for subsequent research. After drawing the Venn diagram and matching to Cytoscape, an mRNA-miRNA-lncRNA network linked to the pathogenesis of URSA in dNK cells was constructed. A novel regulatory network of mRNA-miRNA-lncRNA ceRNA is established in dNK cells from patients with URSA. All RNAs might be used as the biomarkers of the pathogenesis of URSA.

Research progress of immune balance and genetic polymorphism in unexplained recurrent abortion

The etiology of recurrent spontaneous abortion (RSA) is extremely complex, as there are 40–50% of patients with unexplained miscarriages, known as unexplained RSA (URSA). URSA affects approximately 1–2% of females of childbearing age and has a massive impact on the physical and mental conditions of both patients and their families. The pathogenesis of the disease remains unclear, making its treatment complicated. In recent years, considerable progress has been made in the exploration of the URSA immune balance mechanism and it has been universally acknowledged that a balanced immune response (as abnormal immunity) may be the root cause of poor pregnancy outcomes. This review discussed and summarized the effects of immune cells and blocking antibodies (BAs) on URSA based on the current state of knowledge in this area. Additionally, molecular genetics also plays an essential role in the incidence rate of URSA since the role of genetic polymorphism in the pathogenesis of URSA has been thoroughly studied. Nonetheless, the outcomes of these studies are inconsistent, particularly across populations. This paper reviewed previous studies on URSA and maternal genetic polymorphism, focusing on and synthesizing the most important findings to date, and providing diagnostic recommendation for URSA patients with clinical symptoms.

Proteomic profiling analysis of human endometrium in women with unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) seriously affects female reproductive health, causing a great burden to patients both physically and mentally. Endometrial decidualization plays an important role in pregnancy, and impaired decidualization is an essential cause of URSA, but the cause of the damage is still poorly understood. This study aimed to reveal the pathogenesis of URSA by analyzing the differential protein expression profiles in the decidual tissue of patients with recurrent abortion compared to those with normal pregnancy. Morphological analysis revealed abnormal decidualization of endometrial tissue in patients with URSA. Quantitative proteomics analysis showed that a total of 146 differentially expressed proteins were identified between the two groups, among which 95 proteins were downregulated and 51 proteins were upregulated. Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed that the protein expression profile and signaling pathways of endometrium in patients with URSA changed significantly, and cytoskeleton remodeling and morphological transformation disorders were associated with abortion induced by incomplete decidualization. Meanwhile, transcription factors analysis showed that the 3 most affected families were zf-C2H2, MYB and HMG. Therefore, our study may provide a basis for searching for potential markers of decidualization injury. SignificanceAt present, there are still about 50% of RSA patients with unknown causes, which brings great difficulties and blindness to clinical diagnosis and treatment.The limited proteomic studies on URSA further contribute to the lack of understanding in this field. However, in this study, the focus was on proteomic profiling analysis of the human endometrium in URSA patients compared to normal women. The findings revealed that cytoskeletal remodeling disorder is a significant contributor to the failure of decidualization in URSA patients. This insight highlights the potential role of cytoskeleton-related proteins in the pathogenesis of URSA, providing valuable information for further research and potential therapeutic interventions.

Integrated analysis of lncRNA and mRNA expression profiles in patients with unexplained recurrent spontaneous abortion.

Unexplained recurrent spontaneous abortion (URSA) is one of the most frustrating and confounding conditions in reproductive medicine, and its exact pathogenesis has not been clearly established. In this study, we used RNA sequencing to characterize the mRNA and lncRNA expression profiles in peripheral blood. Thereafter, enrichment analysis was performed to determine the functions of the differentially expressed genes, and Cytoscape was used to construct lncRNA-mRNA interaction networks. Our results showed that the peripheral blood of patients with URSA has distinct mRNA and lncRNA expression profiles, with a total of 359 mRNAs and 683 lncRNAs being differentially expressed. Moreover, the top hub genes, including IGF1, PPARG, CCL3, RETN, SERPINE1, HESX1, and PRL, were identified and further validated using real-time quantitative PCR. Furthermore, we demonstrated a lncRNA-mRNA interaction network that achieved 12 key lncRNAs and their targeted mRNAs are involved in systemic lupus erythematosus, allograft rejection, and complement and coagulation cascades. Finally, the correlation between immune cell subtypes and IGF1 expression was evaluated; a negative correlation was observed with the proportion of natural killer cells, which increased significantly in URSA. We identified seven top hub genes, constructed a lncRNA-related network and suggested that IGF1 plays a key role in regulating maternal immune response by affecting NK and T cells' function, which helps to identify the pathogenesis of URSA.

Low-dose aspirin protects unexplained recurrent spontaneous abortion via downregulation of HMGB1 inflammation activation.

High mobility group box protein 1 (HMGB1) is considered as a kind of sterile inflammatory mediators, which is an overexpression in patients with unexplained recurrent spontaneous abortion (URSA). Specific targeting effect of aspirin on HMGB1 has been revealed. Our previous studies have explored the application of HMGB1 as a therapeutic target of aspirin in URSA disease of mice model and human, but the dynamic process of aspirin downregulating HMGB1 concentration has not been demonstrated. From December 2018 to November 2020, women with URSA (n = 91) and control women (n = 90) with no history of recurrent abortion or adverse pregnancy were included in the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University. ELISA was applied to detect the concentrations of HMGB1 and IFN-γ in the peripheral blood. Thirty-one URSA patients were monitored for low-dose aspirin treatment (2 and 4 weeks), the changes of HMGB1 and IFN-γ concentrations in peripheral blood of URSA patients before and after using aspirin were compared, and pregnancy outcomes after aspirin treatment were followed up. The levels of HMGB1 in peripheral blood were significantly higher in URSA patients compared with controls, decreasing trends of HMGB1 and IFN-γ concentrations in plasma of URSA patients were observed after treatment with low-dose aspirin continuously, and the expression of HMGB1 was positively correlated with IFN-γ. There were no birth abnormalities in the babies of the URSA patients treated with aspirin. High levels of HMGB1 may be one of the pathogenesis of URSA. Low-dose aspirin may provide protective effect on the HMGB1-triggered URSA.

MiR-146a-5p enhances embryo survival in unexplained recurrent spontaneous abortion by promoting M2 polarization of decidual macrophages

Unexplained recurrent spontaneous abortion (URSA) is one of the most challenging conditions in the reproductive field, and macrophage M1/M2 polarization disorder is involved in URSA pathogenesis, although the relevant mechanisms are undefined. miR-146a-5p possesses an immunoregulatory role and is expressed in decidual immune cells, and this study aims to investigate its effect on decidual macrophage polarization and therapeutic prospects in URSA, which has never been reported. The levels of M1/M2 markers in the deciduae and the miR-146a-5p expression in the decidual macrophages of URSA and healthy pregnant women were first detected and analyzed. Then, the in vitro effect of miR-146a-5p on the M1/M2 polarization and the secretion of inflammatory cytokines was investigated in Tamm-Horsfall protein-1 (THP-1)-induced macrophages. Finally, the in vivo immunotherapeutic effect of miR-146a-5p on embryo survival and the potential mechanisms were evaluated in a murine model of immune-based URSA. As a result, the abnormal M1/M2 polarization, which showed a shift towards the M1 phenotype and correlated with the decreased expression of miR-146a-5p, was verified in human URSA decidual macrophages. miR-146a-5p could inhibit M1 polarization, promote M2 polarization, and result in an anti-inflammatory microenvironment in THP-1-induced macrophages. The intravenous injection of exogenous miR-146a-5p in the first trimester of pregnant URSA mice significantly reduced the embryo resorption rate and promoted the M2 polarization of decidual macrophages. In conclusion, miR-146a-5p enhances embryo survival in URSA by promoting decidual macrophage polarization toward an M2 phenotype, giving new ideas and potential targets for subsequent research on the pathogenesis and immunotherapeutic strategies of URSA.

The alteration and potential relationship of vaginal microbiota and chemokines for unexplained recurrent spontaneous abortion.

The diagnosis and treatment of unexplained recurrent spontaneous abortion (URSA) is an important and hot topic in the field of obstetrics and gynecology. During our clinical investigation (observation), we have found that URSA patients usually experience recurrent vaginitis or vaginal dysbacteriosis during periods of non-pregnancy, pregnancy, and post-abortion. However, there is no research on vaginal dysbacteriosis's influence on URSA. Using women with normal induced abortion as a control group, and using 16S rRNA sequencing, which helps to screen differentially expressed flora, this study discusses the relevance between differential bacteria at the genus level and the incidence of URSA. Another aim of this study is to determine whether certain pathogenic genera can cause an imbalance in immune tolerance of the maternal and fetal interface through regulatory chemokines, which leads to recurrent spontaneous abortion. This article has explored URSA pathogenesis from the perspective of differentially expressed vaginal flora, which has great theoretical significance for the early diagnosis and treatment of URSA.

Foxp3 TSDR Hypermethylation Is Correlated with Decreased Tregs in Patients with Unexplained Recurrent Spontaneous Abortion

A decline of T regulatory cell (Treg) number and function is associated with unexplained recurrent spontaneous abortion (URSA). However, the mechanism of downregulation of Tregs in URSA patients is still unknown. This study aimed to investigate the changes of Tregs in URSA patients and the epigenetic regulation for these changes. Venous blood samples were collected from 20 patients with URSA and 20 healthy control subjects. Treg number and inhibitory capacity, and Foxp3 mRNA expression and Foxp3 TSDR methylation were compared between the 2 groups. Correlations between Treg frequency and inhibitory function and TSDR methylation status were examined by Spearman's correlation. The proportion of Tregs within the population of CD4+ T cells and the expression of Foxp3 mRNA was significantly lower in URSA patients than in healthy control subjects. Tregs from URSA patients and healthy controls both significantly inhibited the cytotoxic activity of natural killer (NK) cells toward K562 targets; however, the inhibitory ability of Tregs from URSA patients was significantly lower than that from healthy controls. The methylation level of the Treg-specific demethylated region (TSDR) in the Foxp3 gene was significantly greater in URSA patients than in the controls, and the level of methylation was inversely correlated with the proportion of Tregs and Foxp3 mRNA expression in the peripheral blood. However, the methylation level was not correlated with the inhibitory function of Tregs. A decrease of Treg number and function may be related to the pathogenesis of URSA, and Foxp3 hypermethylation may be associated with the decreased Treg number.

Distinct changes of in BTLA, ICOS, PD-1, and TIGIT expression on peripheral blood and decidual CD8+ T cells in women with unexplained recurrent spontaneous abortion†.

The two-way communication between the mother and the fetus is accomplished by immune cells. CD8+ T cells of normal pregnant (NP) women express progesterone receptor (PR). Binding of PR to progesterone (P) and the production of progesterone-induced blocking factor (PIBF) can aid immune escape, which is an important factor in the maternal immune response. We detected the proportion of CD8+ T cells and the expression of the surface costimulatory molecules BTLA, TIGIT, ICOS, and PD-1 in peripheral blood and decidual tissues of women with unexplained recurrent spontaneous abortion (URSA) and in NP women. All patients were at 8 -10 weeks of gestation. The results showed that there was no change in the proportions of CD8+ T cells in peripheral blood and decidual tissues of URSA patients compared to those of NP women. In peripheral blood, compared with the NP group, the URSA group showed decreased expression of BTLA + CD8+ T cells and the difference was statistically significant, but there was no difference between the groups in terms of TIGIT + CD8+, PD-1 + CD8+, and ICOS + CD8+ T cells. There was no change in the levels of TIGIT + CD8+, PD-1 + CD8+, ICOS + CD8+, and BTLA + CD8+ T cells in decidual tissue. These data confirm that the number of CD8+ T cells in peripheral blood and decidual tissue is not the main factor leading to the pathogenesis of URSA, and other immune cells may play an important role in URSA, but this hypothesis needs further exploration and research.

Phosphorylated STAT3 inhibited the proliferation and suppression of decidual Treg cells in unexplained recurrent spontaneous abortion

This study aimed to investigate the effects of signal transducer and activators of transcription 3 (STAT3) phosphorylation on the function of decidual regulatory T (Treg) cells in unexplained recurrent spontaneous abortion (URSA) patients and to explore the mechanism of STAT3 in URSA. Treg cells were sorted out from the decidual tissue by magnetic beads. The inhibitor Stattic was utilized to alter the phosphorylation status of STAT3 (pSTAT3) in Treg cells. The proliferation and suppression of Treg cell were detected by flow cytometry, real-time quantitative fluorescent PCR and ELISA. The factors that caused the hyperphosphorylation of Treg cells were detected. Our results showed that the proportion of pSTAT3 cells in the decidual Treg cells of URSA patients was significantly increased. pSTAT3 inhibited the proliferation of Treg cells by downregulating the expression of STAT5 and Foxp3 and increased the number of responder T cells. pSTAT3 decreased the secretion of TGF-β1 and IL-10 in Treg cells. Overexpression of pro-inflammatory cytokines IL-6 and IL-23 stimulated STAT3 phosphorylation in Treg cells. This study suggests that hyperphosphorylation of STAT3 impairs the proliferation, suppression and cytokine secretion of Treg cells, while inhibiting the phosphorylation of STAT3 restores these functions. These findings clarify the role of STAT3 in the pathogenesis of URSA and provide new ideas for the treatment of URSA.

Noncoding RNAs in Unexplained Recurrent Spontaneous Abortions and Their Diagnostic Potential.

Unexplained recurrent spontaneous abortion (URSA) is defined as the loss of two or more consecutive pregnancies before the 20th week of gestation with normal findings on routine screening tests. Our understanding of the cellular and molecular pathogenesis of URSA is still far from complete. Noncoding RNAs (ncRNAs) play a pivotal role in transcription and expression. The functions of ncRNAs may also improve understanding of URSA pathogenesis. Because of their stability in the circulatory system and at the maternal-fetal interface, it may be possible to use ncRNAs as biomarkers for certain disease states. Here, we provide a narrative review of the current state of knowledge about ncRNAs associated with URSA. The possibility of developing a diagnostic tool using ncRNAs is discussed. The underlying mechanisms of how ncRNAs may lead to the onset of URSA are explored in this review.

Expression of Tim-3 in peripheral blood mononuclear cells and placental tissue in unexplained recurrent spontaneous abortion

The expression of T-cell immunoglobulin domain, mucin domain-3 (Tim-3) in unexplained recurrent spontaneous abortion (URSA) was investigated.Tim-3 mRNA expression in peripheral blood mononuclear cells (PBMCs) of URSA and control groups was assayed by fluorescent quantitative real-time polymerase chain reaction. Tim-3 protein expression intensity and localization in placental villi and uterine decidua were determined using immunohistochemical assay. The CD4+Tim-3+/CD4+ cell ratio in PBMCs was determined by flow cytometry.Tim-3 mRNA expression in PBMCs was significantly higher in URSA than in normal controls (1.32 ± 0.25 vs 1.20 ± 0.12, P < .05). Tim-3 was expressed in placental tissue from both URSA patients and normal pregnant females (controls); however, the expression intensity was higher in the URSA group (0.54 ± 0.31 vs 0.35 ± 0.22, P < .05). CD4+Tim-3+/CD4+ cell ratio in PBMCs was significantly higher in the URSA group than that in the control group (4.53 ± 1.66% vs 1.28 ± 0.71%, P < .05).Increased Tim-3 expression in PBMCs and placental tissue of URSA might affect maternal-fetal immune tolerance. Tim-3 was involved in the pathogenesis of URSA, which was expected to serve as an indicator for the immune evaluation of URSA.

Treg/Th17 Cell Imbalance and IL-6 Profile in Patients With Unexplained Recurrent Spontaneous Abortion.

Regulatory T cells (Treg) and T helper 17 cells (Th17) are 2 distinct subsets of CD4+ T cells, which are mutually antagonistic in the immune response. Recently, dysregulation of these 2 cell subsets have been described in the pathogenesis of unexplained recurrent spontaneous abortion (URSA). The purpose of this study was to investigate whether the Treg/Th17 balance was perturbed in URSA patients and to explore contributing factors. We found that the proportion of Treg cells and expression of forkhead box P3 (Foxp3) messenger RNA (mRNA) were significantly lower in URSA patients than in healthy controls. However, the proportion of Th17 cells and expression of retinoid-related orphan nuclear receptor-γt (ROR-γt) mRNA were higher in URSA patients than in controls, revealing inverse correlation with Treg. The ratio of Treg/Th17 and Foxp3/ROR-γt decreased in patients with URSA compared to healthy controls. The serum levels of interleukin (IL)-6 and IL-17A were significantly higher, whereas IL-10 was lower in URSA patients compared with controls, and the level of IL-6 showed a positive correlation with Th17, ROR-γt and inverse correlation with Treg, Foxp3. The present study indicated that an imbalance between Treg and Th17 cells might be implicated in the pathogenesis of URSA and this seems to relate to elevation in serum IL-6 level.

Differences in Cytokine Expression and STAT3 Activation between Healthy Controls and Patients of Unexplained Recurrent Spontaneous Abortion (URSA) during Early Pregnancy.

Unexplained recurrent spontaneous abortion (URSA) is a common complication of pregnancy. Although tolerance of the maternal immune system is considered to be essential for a normal pregnancy, the precise mechanism underlying the pathogenesis of URSA remains to be fully elucidated, albeit it is known to involve inflammation. Here, we examine the relationship between the expression of inflammatory cytokines and the activation of downstream signaling pathways in URSA patients. Decidual and peripheral blood samples were collected from 30 URSA patients and from 30 women with normal early pregnancies. Western blot analysis was used to measure the expression levels of signal transducers and activators of transcription 3(STAT3), phosphorylated STAT3(p-STAT3), and interleukin-17 receptor(IL-17R) in the decidual samples. Enzyme-linked immunosorbent assay was used to assess the levels of IL-17, IL-10, IL-6, and IL-23 in the peripheral blood and decidual samples. In the URSA patients, the IL-10 expression levels were lower than those in the control subjects (P<0.05), whereas IL-6, IL-17, and IL-23 were all expressed at higher levels(P<0.05). Furthermore, the expression levels of IL-17R and p-STAT3 were higher in the URSA patients, exhibiting a trend similar to that of IL-23. Our finding of increased IL-23 expression in the deciduae and peripheral blood of patients with URSA suggest that this maybe a contributing factor to the pathogenesis of this disease. Likewise, STAT3 activation through its phosphorylation, which was associated with the IL-23 increase, may also be involved in URSA pathogenesis. However, the precise pathogenic mechanism requires further study.

Association between the C46T polymorphism of coagulation factor Ⅻ gene and the involvement of factor Ⅻ activity in patients with unexplained recurrent spontaneous abortion

To explore the association between the C46T polymorphism of coagulation factor Ⅻ (FⅫ) gene and the involvement of FⅫ activity (FⅫ:C) in patients with unexplained recurrent spontaneous abortion (URSA), and to elucidate its role in the pathogenesis of URSA. This study included 203 patients with URSA (URSA group) and 171 healthy women with at least one child and no history of infertility or miscarriage (control group) in the southern area of Zhejiang Province. The C46T polymorphism of the FⅫ gene was analyzed with matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF-MS) in all subjects. The values of prothrombin time, activated partial thromboplastin time (APTT), fibrinogen, FⅫ:C and other coagulant parameters were determined. The frequency distribution of the wild-type (CC), heterozygote (CT), homozygote (TT) genotypes and C and T alleles were compared between the patients and controls. A comprehensive analysis of association was conducted between C46T genotypes and the FⅫ:C levels in URSA patients. The CC, CT, TT genotypes of the FⅫ gene were observed in 7 (3.4%, 7/203), 83 (40.9%, 83/203) and 113 (55.7%, 113/203) patients with URSA versus 7 (4.1%, 7/171), 46 (26.9%, 46/171) and 118 (69.0%, 118/171) controls. The frequency of CT in the patients with URSA was significantly higher than that in controls, but the frequency of TT in the patients was lower than that in controls (χ(2)=7.939, OR=1.884, 95%CI: 1.210-2.935, P<0.05). The frequencies of allele C and allele T were observed in 97 (23.9%, 97/406) and 309 (76.1%, 309/406) patients with URSA versus 60 (17.5%, 60/342) and 282 (82.5%, 282/342) controls. The distribution frequency of allele T in URSA group was lower than that in control group (χ(2)=4.510, OR=1.475, 95%CI: 1.029-2.115, P<0.05). The FⅫ: C levels in the patients were (102±13)% in CC genotype, (78±11)% in CT genotype and (59±9)% in TT genotype, respectively. The differences of the FⅫ: C levels between the CC and CT, CT and TT, CC and TT genotypes in the patients were significant (all P<0.05). The low level of FⅫ:C maybe result from the T allele of the FⅫ gene in URSA patients. The CT genotype might be relative to the pathogenesis of URSA in a Chinese Han female population from the southern area of Zhejiang province.

Potential role of circulating microRNAs as a biomarker for unexplained recurrent spontaneous abortion

To compare circulating microRNA (miRNA) profiles between unexplained recurrent spontaneous abortion (URSA) and normal early pregnancies (NEP) and to evaluate the potential role of circulating miRNA as a biomarker for URSA. Laboratory study using human plasma samples. Special hospital and research institutes. From September 2012 to April 2013, samples of plasma were obtained from 27 URSA patients and 28 NEP patients at 6-10weeks of gestation at the Department of Reproductive Immunology in Family Planning Special Hospital of Guangdong Province. Differential miRNA profiling analysis of plasma collected from URSA and NEP patients was performed with the use of microarray. The circulating miRNA expression profile was assessed by means of microarray and real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis. Twenty-five circulating miRNAs were expressed differentially in URSA compared with NEP. Of these, nine were overexpressed and 16 down-regulated. Six differentially expressed circulating miRNAs were selected to validate the microarray results, and qRT-PCR data confirmed the reliability of the microarray results. Further analysis showed that four circulating miRNAs (miR-320b, miR-146b-5p, miR-221-3p, miR-559) were up-regulated. In URSA, one circulating miRNA (miR-101-3p) was down-regulated in other larger scale samples according to qRT-PCR. Based on target gene analysis, we speculate that these circulating miRNAs regulate URSA by targeting immune, apoptosis, and angiogenic gene functions. Circulating microRNAs may be involved in URSA pathogenesis and provide a promising new diagnostic biomarker for URSA.

Th17 cells and related cytokines in unexplained recurrent spontaneous miscarriage at the implantation window

Unexplained recurrent spontaneous abortion (RSA) might be caused by the mother's immunological rejection of the fetus. In this cross-sectional study, the percentage of T helper 17 (Th17), T regulatory (Treg) cells and their cytokines as the main players of immunomodulation in peripheral blood lymphocytes during the luteal phase of 20 women with unexplained RSA were compared with 20 normal non-pregnant women. The percentage of Treg cells in the former was significantly lower compared with controls. The percentage of Th17 cells in the former was higher than controls. Expression of IL-23, IL-17, IL-6 cytokines in the former was significantly higher than controls, but the higher expression of IL-21 was not significant. The gene expression of TGF-β and FoxP3 in the former was lower than controls. Significant positive correlations were found between the percentage of Th17 cells with IL-23, IL-6 and IL-17 and between expression of IL-23 and IL-6 and IL-17. IL-6 gene expression showed a significant positive correlation with IL-17. Therefore, imbalance of Th17–Treg cells and the consequent changes in cytokine expression might be implicated in the pathogenesis of unexplained RSA and may provide new insight into the immunoregulatory events at the maternal–fetal interface.

The relationship between polymorphisms in the promoter region of Tim-3 and unexplained recurrent spontaneous abortion in Han Chinese women

BackgroundRecurrent spontaneous abortion (RSA) refers to 2 or more consecutive pregnancy losses, and RSA with unknown causes is called unexplained recurrent spontaneous abortion (URSA). Tim-3, a subtype of the T-cell immunoglobulin domain and mucin domain (Tim) protein family, might be an important regulatory molecule that plays a pivotal role in URSA, which might be triggered mostly by Th1/Th2 immune deviation. To understand the etiology and pathogenesis of URSA in Han Chinese women, we investigated the association between polymorphisms of rs10053538 and rs10515746 in the promoter of Tim-3 and the risk of URSA in Han Chinese women.MethodsOne hundred and forty-eight women with RSA resulting in still birth were enrolled in the URSA group. We performed tests to rule out congenital reproductive system malformation, reproductive system tumor, endocrine dyscrasia, and chromosome abnormalities. One hundred and fifty-three women with normal pregnancy leading to live birth were selected at random to comprise the control group. All women included in this study were genetically unrelated Han Chinese women. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele-specific polymerase chain reaction (AS-PCR) were used to determine polymorphisms of rs10053538 and rs10515746, respectively, in all subjects. PCR products were chosen at random for sequencing.ResultsNo significant statistical difference was found between the distribution frequency of the GT + TT genotype and T allele on the rs10053538 locus in the URSA group or the control group (10.1% vs. 11.8%, Chi(2) = 0.205, P = 0.651; 5.1% vs. 6.5%, Chi(2) = 0.592, P = 0.441; respectively). Neither was there a significant difference between the distribution frequency of the GT + TT genotype and T allele on the rs10515746 locus in the groups (6.8% vs. 3.9%, Chi(2)1.201, P = 0.273; 3.4% vs. 2.0%, Chi(2) = 1.169, P = 0.280; respectively).ConclusionsThe present study suggested that these polymorphisms of rs10053538 or rs10515746 in the Tim-3 promoter may not be associated with URSA in Han Chinese women.

Changes of CD4 +CD25 high regulatory T cells and FOXP3 expression in unexplained recurrent spontaneous abortion patients

To investigate the proportions of CD4+CD25high T cells and forkhead box p3 (FOXP3) expression in peripheral blood and decidua in patients with unexplained recurrent spontaneous abortion (URSA). Prospective clinical study. University hospital. 125 URSA patients, 35 normal early pregnant women, and 28 normal nonpregnant women. Measurements of CD4+CD25high T cells and FOXP3 expression in peripheral blood and decidua. The proportions of CD4+CD25high T cells and FOXP3 expression. In peripheral blood, statistically significantly higher proportions of CD4+CD25high T cells and FOXP3 expression were observed in normal early pregnant women compared with normal nonpregnant women and URSA patients; a statistically significantly lower proportion of CD4+CD25high T cells was observed in nonpregnant URSA patients compared with URSA patients who had early miscarriages and normal nonpregnant women. In the decidua, statistically significantly lower proportions of CD4+CD25high T cells and FOXP3 expression were found in URSA patients with early miscarriages compared with normal early pregnant women. The CD4+CD25high T cells may play an important role in maintaining a normal pregnancy. The reduction in CD4+CD25high T cells may involve in the pathogenesis of URSA, and is correlated with lower FOXP3 expression.