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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.

Background Maternally Expressed Gene 3 (MEG3) is expressed at low levels in placental villi during preeclampsia; however, its roles in unexplained recurrent spontaneous abortion (URSA) remain unclear. In this study, we aimed to explore the relationship between MEG3 and URSA. Methods The differentially expressed lncRNAs (MEG3) and its downstream genes (RASA1) were identified using bioinformatics analysis of Genomic Spatial Event (GSE) database. The expression levels of MEG3 in embryonic villis (with gestational ages of 49–63 days) and primary trophoblasts were determined using quantitative RT-PCR assay. A mouse model of Embryo implantation, Cell Counting Kit-8 (CCK-8), flow cytometry, and Transwell migration assays were performed to determine the implantation, proliferative, apoptotic, and invasive capacities of trophoblast. The level of phosphorylated core proteins in the RAS-MAPK pathway were analyzed using Western blot assay. The mechanisms of MEG3 in the regulation of RASA1 were studied by RNA pulldown, RNA immunoprecipitation (RIP), DNA pulldown, and chromatin immunoprecipitation (ChIP) assays. Results MEG3 had a low expression level in embryonic villis of 102 URSA patients compared with those of 102 normal pregnant women. MEG3 could promote proliferation and invasion, inhibit the apoptosis of primary trophoblast of URSA patients (PT-U cells), as well as promote embryo implantation of mouse. Besides, MEG3 also promoted the phosphorylation of rapidly accelerated fibrosarcoma (Raf), mitogen-activated protein kinase kinase (MEK), and extracellular-signal-regulated kinase (ERK) proteins. The results of RNA pull down and RIP assays showed that MEG3 bound with the enhancer of zeste homolog 2 (EZH2). The DNA pulldown assay revealed that MEG3 could bind to the promoter sequence of the RAS P21 Protein Activator 1 (RASA1) gene. Further, the ChIP assay showed that MEG3 promoted the binding of EZH2 to the promoter region of the RASA1 gene. Conclusions The inactivation of MEG3 in embryonic villi association with URSA; MEG3 inhibited the expression of RASA1 by mediating the histone methylation of the promoter of RASA1 gene by EZH2, thereby activating the RAS-MAPK pathway and enhancing the proliferative and invasive capacities of trophoblasts.

Recurrent spontaneous abortions (RSA) is defined as three or more consecutive pregnancy losses before 20 weeks of gestation. Various causes of RSA have been identified, still 50% cases remain unexplained after evaluation. One of the causes of unexplained recurrent spontaneous abortions (URSA) is supposed to be the disruption of immunological tolerance at foeta–maternal interface. Regulatory T cells (Tregs) are responsible for the development of immune-tolerant environment at foetal–maternal interface and supports pregnancy. Forkhead/winged helix transcription factor (FOXP3) gene plays an important role in the development and function of Tregs. In URSA, Tregs (CD4+CD25+) are reduced in peripheral blood and decidua of pregnant women. This reduction of Tregs (CD4+CD25+) is associated with decreased expression of FOXP3 gene. This study evaluated the association between single-nucleotide polymorphisms (SNPs) in FOXP3 gene and URSA in Indian population. In this study, 100 patients with a history of URSA and 100 healthy ethnically matched women with at least one normal pregnancy and no abortion were included as case and control groups, respectively. Four SNPs of FOXP3 gene, two in the promoter region: $$-924\hbox {A/G}$$ and $$-3279\hbox {C/A}$$ , and two intronic, $$-20\hbox {G/A}$$ and $$+459\hbox {T/C}$$ , were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). $$-924\hbox {A/G}$$ and $$+459\hbox {T/C}$$ polymorphisms were found to be associated with URSA. $$-3279\hbox {C/A}$$ and $$-20\hbox {G/A}$$ polymorphism were not found to be associated with URSA. The odds ratio (OR) of mutant allele G for $$-924\hbox {A/G}$$ polymorphism was 2.5 (95% CI 1.7–3.8; $$P< 0.001$$ ) and mutant allele C for $$+459\hbox {T/C}$$ polymorphism was 1.7 (95% CI 1.1–2.6; $$P = 0.01$$ ). For $$-20\hbox {G/A}$$ polymorphism, only GG genotype was found in both URSA and controls. These results suggest that $$-924\hbox {A/G}$$ and $$+459\hbox {T/C}$$ polymorphisms of the FOXP3 gene might be associated with URSA and $$-20\hbox {G/A}$$ polymorphism is likely to be rare in Indian population and might not be associated with URSA.

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.

This paper contributes to the solution of several open problems with parallel programming tools and their integration with performance evaluation environments. First, we propose interactive compilation scenarios instead of the usual black-box-oriented use of compiler tools. In such scenarios, information gathered by the compiler and the compiler's reasoning are presented to the user in meaningful ways and on-demand. Second, a tight integration of compilation and performance analysis tools is advocated. M any of the existing, advanced instruments for gathering performance results are being used in the presented environment and their results are combined in integrated views with compiler information and data from other tools. Initial instruments that assist users in “data mining” this information are presented and the need for much stronger facilities is explained. The URSA Family provides two tools addressing these issues. URSA MINOR supports a group of users at a specific site, such as a research or development project. URSA MAJOR complements this tool by making available the gathered results to the user community at large via the World-wide Web. This paper presents objectives, functionality, experience, and next development steps of the URSA tool family. Two case studies are presented that illustrate the use of the tools for developing and studying parallel applications and for evaluating parallelizing compilers.

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