CD4+CD25+FoxP3+ regulatory T cells and cytokines interact with estradiol in cases of missed abortion

The Relationship Between the Average Decreased Times of Estradiol and Early Miscarriage: An Observational Study

Decreased estradiol (E2) levels are associated with early miscarriage (EM), but the relationship between decreased times of E2 and EM has not been reported. We aimed to investigate the relationship between the average decreased times of E2 (ADTE) and EM. Women with a history of miscarriage were retrospectively recruited from the Reproductive Center of Lanzhou University Second Hospital (Lanzhou, China) between September 2019 and February 2022. Based on pregnancy outcome, they were divided into ongoing pregnancy group (n = 359) and EM group (n = 104). In addition, subgroup analyses were performed for the number of previous miscarriages and whether E2 levels decreased continuously. The exposure and outcome variables were ADTE and miscarriage before 12 weeks of gestation, respectively. Totally, 1171 patients were recruited and 463 patients were finally analyzed. ADTE was associated with EM (odds ratio [OR] = 1.346, 95% confidence interval [CI]1.154-1.571, P < 0.001). When ADTE ≥ 2.5, the EM risk increased 1.17-fold compared to patients with 0-1.249 times (OR = 2.170, 95% CI 1.144-4.117, P = 0.018). Moreover, a threshold effect existed in the ADTE and the risk of EM with a value of 4.9 times. When exceeding 4.9 times, the EM risk increased 4.713-fold for each increased unit (OR = 5.713, 95% CI 1.255-23.170, P = 0.024). Subgroup analysis showed that ADTE had a greater effect on the occurrence of EM in women with a history of 1-2 miscarriages than in women with 3 miscarriages. Decreased E2 was a risk factor for EM regardless of whether it dropped continuously or not. In conclusion, our study identifies a potential link between ADTE and early miscarriage risk in women with prior miscarriages, yet cautious interpretation is necessary due to inherent design limitations. Further research with prospective designs and large population samples is essential to validate ADTE's utility as a predictive indicator for early miscarriage in clinical settings.

Estradiol in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune polymorphous disease that primarily affects women of reproductive age. This gender disparity has suggested the importance of investigating the role of reproductive hormones in the pathogenesis of the disease. Estradiol, the most potent form of estrogen, plays a key role in shaping the immune system including the production of lymphocytes, the peripheral differentiation of regulatory T cells (T-regs), antibody production, and the complement and interferon systems, and has been studied in the pathogenesis of systemic lupus erythematosus (SLE). It operates by binding to estrogen receptors (ERs) α and β, initiating cellular responses including alterations in gene expression. Regulatory T cells are instrumental in preserving immunological self-tolerance and moderating immune responses. Estradiol's serum levels correlate with the expansion of CD4+CD25+ and FoxP3+ in healthy females. However, this response is reduced in lupus patients. Estradiol also interacts with microRNAs (miRNAs) in gene regulation. Hsa-miR-10b-5p, a miRNA targeting SRSF1, is overexpressed in SLE patients and its levels increase with exposure to estrogens. Other miRNAs also show correlation with plasma Estradiol levels. The precise role of Estradiol in the pathogenesis of SLE remains complex and multifaceted and is a topic for further research.

Distinct mRNA and long non-coding RNA expression profiles of decidual natural killer cells in patients with early missed abortion

Early non-chromosome-related missed abortion (MA) is commonly associated with an altered immunological environment during pregnancy. Human decidual natural killer (dNK) cells, the most abundant lymphocyte population within the first-trimester maternal-fetal interface, are vital maternal regulators of immune tolerance mediating successful embryo implantation and placentation. Previous studies have shown that dNK cells may play a role in MA. However, the gene expression status and specific altered manifestations of dNK cells in patients with early MA remain largely unknown. Here, we show that MA dNK cells have distinct mRNA and lncRNA expression profiles through RNA sequencing, with a total of 276 mRNAs and 67 lncRNAs being differentially expressed compared with controls. Protein-protein interaction analysis of differentially expressed mRNAs was performed to identify hub genes and key modules. An lncRNA-mRNA regulatory network characterized by the small-world property was constructed to reveal the regulation of mRNA transcription by differential hub lncRNAs. Functional annotation of differentially expressed mRNAs and lncRNAs was performed to disclose their potential roles in MA pathogenesis. Our data highlight several enriched biological processes (immune response, inflammatory response, cell adhesion, and extracellular matrix [ECM] organization) and signaling pathways (cytokine-cytokine receptor interaction, ECM-receptor interaction, Toll-like receptor signaling pathway, and phosphatidylinositol signaling system) that may influence MA. This study is the first to demonstrate the involvement of altered mRNA and lncRNA expression profiles in the dNK cell pathogenesis of early MA, facilitating a better understanding of the underlying molecular mechanisms and the development of novel MA therapeutic strategies targeting key mRNAs and lncRNAs.

Is there a role for HLA-G in the induction of regulatory T cells during the maintenance of a healthy pregnancy?

PROBLEM

Pregnancy remains an immune challenge for the uterus that has to adapt to a semi-allogeneic fetus using various regulatory mechanisms. Both HLA-G and regulatory T cells (CD4⁺  CD25⁺  FOXP3⁺  T_regs ) are upregulated in successful pregnancy, but not in abortion. It is unclear if HLA-G plays a role in the upregulation of regulatory cells.

METHOD OF STUDY

We measured the level of both sHLA-G and T_reg  cells in the blood of healthy pregnant multigravida, unexplained recurrent spontaneous abortions (URSA) and healthy non-pregnant and nulliparous females. We cultured peripheral blood lymphocytes of healthy non-pregnant multigravida females who never had an abortion with lymphocytes of their partners at ratio of 1:1, with and without sHLA-G to detect changes in number of T_reg  cells, or relevant cytokines.

RESULTS

Soluble HLA-G concentrations and T_reg  cells percentage were significantly lower in women with URSA as compared to healthy pregnant multigravida women and were comparable to healthy non-pregnant nulliparous women. Percentage of T_regs  increased between zero time and mixed lymphocyte cultures (MLC) in both cultures with and without recombinant sHLA-G but no significant difference between the two cultures. When stimulated with sHLA-G the mean extracellular IL-10 concentration was unchanged, while the mean INF-γ concentration was slightly higher with no significant difference. Intracellular TGF-β was higher in CD4⁺  cells after incubation with sHLA-G.

CONCLUSION

The results of this study are consistent with previous studies on the role of sHLA-G and T_reg  cells in inducing immune-tolerance in pregnancy. The results also suggest a possible role for HLA-G in the enrichment of T_reg  cells.

Analysis of chromosomes and the T helper 17 and regulatory T cell balance in patients with recurrent spontaneous abortion

The present study investigated the genetic etiology and possible immunological pathogenesis of recurrent spontaneous abortion by analyzing chromosome abnormalities, and the balance between T helper 17 (Th17) and regulatory T (Treg) cells. A total of 54 patients with recurrent spontaneous abortion were selected. The villus and decidual tissues, and peripheral venous blood were collected from each patient. Villus chromosome analysis was performed by high-throughput gene sequencing. Flow cytometry was used to detect Th17 and Treg cells in patients without chromosome abnormalities (n=30) and the control group (normal pregnancy; n=32). Immunoglobulin (IG) combined with human chorionic gonadotropin hormone (HCG) treatment was given to patients without chromosome abnormalities (n=30). Changes in the expression levels of Th17 and Treg cells before and after treatment were compared with patients with successful pregnancy (n=18). Before treatment, compared with the control group, the proportion of Th17 cells in peripheral blood and decidual tissue was increased and the proportion of Treg cells decreased. After treatment, compared with patients before treatment, the proportion of Th17 cells decreased and Treg cells increased, and the Th17 and Treg cells balance was reversed with a biased towards Treg cells. The present results suggested that the Th17 and Treg cell immune imbalance may be an important immune factor in recurrent spontaneous abortion. IG combined with HCG therapy may improve pregnancy outcomes by reversing the imbalance between Th17 and Treg cells.

Pigment epithelium‑derived factor facilitates NLRP3 inflammasome activation through downregulating cytidine monophosphate kinase 2: A potential treatment strategy for missed abortion

A number of conditions may underlie the occurrence of missed abortion (MA), including inflammation. Pigment epithelium‑derived factor (PEDF) is a novel mediator of the inflammation‑related nucleotide‑binding oligomerization domain‑like receptor protein 3 (NLRP3) inflammasome, which is associated with several human diseases. However, the association between MA and NLRP3 inflammasome, and whether PEDF is reduced in MA, remain unknown. In the present study, the decidua and chorion tissues of patients who had suffered a MA were examined, and a lipopolysaccharide (LPS)‑induced human chorionic trophoblast HTR8/SVneo cell model was established to mimic MA in vitro. The results revealed that cytidine monophosphate kinase 2 (CMPK2) expression and NLRP3 inflammasome activation, downstream pro‑IL‑18 and pro‑IL‑1β expression, and IL‑18 and IL‑1β release, were all significantly increased in MA tissues or LPS‑induced HTR8/SVneo cells. PEDF reversed the increase in CMPK2 expression and activation of the NLRP3 inflammasome axis and, thus, downregulated the production of mitochondrial reactive oxygen species and mitochondrial DNA release, resulting in reduced lactate dehydrogenase release, and a resultant decrease in cell viability. Recovery of CMPK2 expression abolished all the effects of PEDF, indicating that CMPK2 may be an effector downstream of PEDF. PEDF reduced CMPK2 protein levels but did not affect the mRNA levels, and treatment with the proteasomal inhibitor MG132 significantly reversed this reduction in CMPK2 protein levels. Furthermore, a ubiquitination assay of immunoprecipitation demonstrated that CMPK2 was polyubiquitinated in the presence of LPS, PEDF and MG132. These results indicated that the NLRP3 inflammasome is implicated in the pathogenesis of MA, and PEDF may reduce MA through ubiquitin‑dependent proteasomal degradation of CMPK2 to inhibit NLRP3 activation, which may serve as a novel strategy for preventing or reducing the risk of MA.

Expression of galectin-3 and apoptosis in placental villi from patients with missed abortion during early pregnancy

The success of a pregnancy relies on moderate trophoblast apoptosis. If the 'inhibition-induction' balance of apoptosis is broken, a pathological pregnancy may occur. Galectin-3 has an important role in numerous biological processes, including tumor cell apoptosis. However, the association between galectin-3 and missed abortion (MA) has remained elusive. In the present study, the mRNA and protein expression levels of galectin-3 in placental villi, and the apoptotic index of placental cells from patients with MA were assessed and compared with those in a normal spontaneous abortion group. The present study investigated the function of galectin-3 in the process of MA and the possible association between placental apoptosis and galectin-3 expression in MA patients. Furthermore, the role of galetin-3 in patients with MA at different times (<4 and >4 weeks) was explored. The present study provided a potential mechanism of MA from a perspective of apoptosis and also provided potential therapeutic approaches to prevent MA.

First trimester β-hCG and estradiol levels in singleton and twin pregnancies after assisted reproduction

Objective To compare levels of β-hCG and estradiol collected during the first trimester in singleton and twin pregnancies following assisted reproduction technologies (ART). Methods We prospectively evaluated 50 singleton and 47 dichorionic twin pregnancies that eventually ended in live births. Patients were recruited from a single ART center with standard treatment protocols followed by fresh embryo transfers. Hormone measurements were performed within a narrow gestational age range and analyzed in a single laboratory thus minimizing inter- and intra-assay variability. We measured serum β-hCG at 13 days after embryo transfer as well as samples of β-hCG and estradiol at 8-9 weeks+6 days. Results No significant differences existed between singletons and twins in respect to demographic and cycle characteristics. β-hCG and estradiol were all significantly higher in twins (P<0.05). Conclusion The data confirms the higher levels of β-hCG and estradiol in twins, pointing to the potential role of these placental hormones in early support of a twin pregnancy.

Estradiol Attenuates the Severity of Primary Toxoplasma gondii Infection-Induced Adverse Pregnancy Outcomes Through the Regulation of Tregs in a Dose-Dependent Manner

Estradiol (E2) plays a crucial and intricate role during pregnancy to mediate several aspects of the pregnancy process. A perplexing phenomenon in congenital toxoplasmosis is that the severity of Toxoplasma gondii (T. gondii)-mediated adverse pregnancy outcome is closely related with time of primary maternal infection during pregnancy. In this study, the results showed that T. gondii infection in early pregnancy was more likely to induce miscarriage in mice than in late pregnancy, which may be related to inflammation of the maternal–fetal interface. Meanwhile, the T. gondii infection-induced-apoptotic rate of Tregs was higher and the expression of programmed death-1 (PD-1) on Tregs was lower in early pregnancy than in late pregnancy. As the level of E2 in mouse serum gradually increased with the development of pregnancy, we proposed that E2 may contribute to the discrepancy of Tregs at different stages of pregnancy. Thus, we investigated in vitro and in vivo effects of E2 in regulating Tregs. We found that E2 in vitro could protect Tregs against apoptosis and upregulate the expression of PD-1 on Tregs in a dose-dependent manner through ERα. Likewise, the simulated mid-pregnancy level of E2 in nonpregnant mice also alleviated the T. gondii infection-induced apoptosis of Tregs and potentiated the PD-1 expression on Tregs. Therefore, in the pathogenesis of T. gondii-induced abnormal pregnancy, E2 helped maintain the immune balance and improve the pregnancy outcome through regulating Tregs. This finding illustrates the intricate working of hormone–immune system interaction in infection-induced abnormal pregnancy.

Maternal lipids, BMI and IL-17/IL-35 imbalance in concurrent gestational diabetes mellitus and preeclampsia

The objective of the present study was to investigate the role of blood glucose, lipid metabolism, body mass index (BMI), C-reactive protein (CRP) as well as an interleukin (IL)-17/IL-35 imbalance in the pathogenesis of concurrent gestational diabetes mellitus (GDM) and preeclampsia (PE) (DPE). The mRNA expression of forkhead box protein 3 (FoxP3), IL-35 [including Epstein-Barr virus-induced gene 3 (EBI3) and P35 subunits] and IL-17 in the peripheral blood mononuclear cells of patients with DPE (n=30), GDM (n=33), PE (n=33) and normal pregnancy (n=33) were determined by reverse transcription-quantitative polymerase chain reaction. The serum levels of IL-35, IL-17 and CRP were analyzed using ELISA. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL) and fasting blood glucose (FBG) were also detected. The levels of low-density lipoprotein (LDL) were calculated using the Friedewald formula. Body weight and height were determined in order to calculate the BMI. It was observed that the levels of FBG were markedly elevated in patients with GDM, PE and DPE. In addition, significantly higher serum TG, TC, LDL and very LDL were detected in patients with GDM, PE and DPE compared with those in subjects with normal pregnancies. By contrast, the concentration of HDL was lower in the patient groups. In addition, higher BMI values were identified in patients with GDM, PE and DPE. A decreased expression of FoxP3, P35 and EBI3 mRNA, and an elevated expression of IL-17 in PBMCs was detected in patients with GDM, PE and DPE. In addition, higher serum levels of IL-17 and CRP, as well as lower levels of IL-35, were observed. Furthermore, in patients with DPE, positive correlations of diastolic blood pressure with IL-17 levels, BMI and TG, as well as IL-17 levels with BMI and proteinuria were identified. In conclusion, the present study indicated that abnormal maternal lipids, hyperglycemia, high BMI, high CRP and IL-17/IL-35 imbalance may have a role in the pathophysiology of DPE. Therefore, pregnant women and clinicians should be made aware that maternal hyperlipidaemia, hyperglycemia, high BMI, high CRP levels and IL-17/IL-35 imbalance may lead to DPE.

Abnormal expression of microRNA-575 leads to missed abortion through regulating apoptosis and angiogenesis

Numerous microRNA (miR) are important for placental development and function. miR-575 has been demonstrated to be upregulated in maternal placenta in patients who have experienced a miscarriage. The present study aimed to explore the role of abnormal expression of miR-575 in missed abortion (MA) and to further analyze the potential molecular mechanisms. Embryo villus tissue samples were extracted from 10 childless women with MA and 10 fertile women without a history of MA. Additionally, human choriocarcinoma cells, JEG-3, were used in the present study, which were transfected with miR-575 mimic, inhibitor and scramble. The expression of miR-575 in embryo villus tissues and in JEG-3 cells was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Apoptosis in villus tissues of patients with MA and in JEG-3 cells of miR-575 mimic, inhibitor and scramble groups were detected by flow cytometry. Furthermore, the expression levels of apoptosis-related proteins, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and phosphorylated (p)-p53, and angiogenesis-related proteins, including vascular endothelial growth factor (VEGF) and angiopoietin 2 (Ang-2), were measured by RT-qPCR and western blotting. Additionally, the target of miR-575 was predicted and clarified by luciferase reporter assay. miR-575 was significantly overexpressed in MA villus tissue compared with normal tissue (P<0.05). The percentage of apoptotic cells in MA embryo villus tissue was significantly higher than that in normal tissue (P<0.05). After JEG-3 cells were transfected with miR-575 inhibitor, the expression of miR-575 and the percentage of apoptotic cells decreased significantly compared with the control (P<0.05). MiR-575 suppression significantly increased the expression of Bcl-2 (P<0.05), and decreased the expressions of Bax (P<0.05) and p-p53 (P<0.01) compared with the control. Furthermore, miR-575 suppression significantly increased the expressions of angiogenesis-related proteins, Ang-2 and VEGF (P<0.01). Superoxide dismutase 2 was identified as the target of miR-575. Therefore, abnormal expression of miR-575 may lead to MA through regulating apoptosis and angiogenesis. Inhibition of miR-575 may inhibit apoptosis and promote angiogenesis in MA.

A shift in the balance of T17 and Treg cells in menstrual blood of women with unexplained recurrent spontaneous abortion

To determine usefulness of menstrual blood for assessment of differential frequency of T cell subsets, peripheral blood (PB) and menstrual blood (MB) from healthy fertile (n=15), unexplained recurrent spontaneous abortion (URSA) women (n=15) and unexplained infertile women (n=8) were collected in the second day of menstrual bleeding. Frequency of T cell subsets was measured by flow cytometry. URSA and unexplained infertile patients had higher frequency of TCRαβ(+)CD3(+)CD56(-) and CD45RO(+) T cells as well as CD45RO(+)/CD45RO(-) ratio in PB as compared to MB. Frequency of CD3(+)TCRγδ(+) cells in PB of unexplained infertile and MB of URSA patients were significantly lower than that in fertile group. In all groups MB contained higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory and lower percentages of CD16(+) T cells compared to PB. T17 cells (CD3(+)CD56(-)IL-17(+)) was found to be significantly higher in MB of only fertile and unexplained infertile subjects and not URSA patients in comparison with PB. Compared to PB, only fertile women had higher T17:Treg ratio in their MB. URSA women had significantly lower MB T17 cells and T17:Treg ratio compared to those in fertile and unexplained infertile women. Based on the findings presented here, we speculate that MB has its own unique immune milieu which is not solely continuation of the immune environment of secretory endometrium. Indeed, immunophenotyping of MB immune cells could potentially be a useful tool for investigation of immunological disturbances in pregnancy-related disorders.

The Expression of Notch/Notch Ligand, IL-35, IL-17, and Th17/Treg in Preeclampsia

The aim of this study was to examine the interaction of Notch/Notch ligand with Th17/Treg, cytokines IL-35 and IL-17 in cases of preeclampsia (PE). Methods. Peripheral blood was obtained from 42 PE patients and 22 health pregnant women. The mRNA expressions of Notch/Notch ligand, Treg transcription factor FoxP3 and Th17 transcription factor RORγt, EBI3 and P35 (IL-35 two subunits), and IL-17 were determined by qPCR. The serum levels of IL-17 and IL-35 were measured by ELISA. Results. It was observed that the expressions of Foxp3, EBI3, and P35 in PE patients were lower compared with normal pregnancy, whereas the RORγt expression was significantly increased. The results also demonstrated that PE patients exhibited decreased levels of Treg-related cytokine IL-35, whereas IL-17 was significantly increased. PE patients expressed higher levels of Notch receptor (1–4) and Notch ligand of DLL4, whereas Notch ligand of Jagged-1, -2 was much lower. Furthermore, the levels of FoxP3 T cells correlated positively with Jagged-2. In addition, there were positive correlations between the mRNA level of IL-17 and DLL4. Conclusion. Our results indicated that maternal immunological changes may reverse maternal tolerance in PE, and this phenomenon may due to the Th17/Treg imbalance affected by Notch/Notch ligand.

Gender differences in autoimmune disease

Autoimmune diseases are a range of diseases in which the immune response to self-antigens results in damage or dysfunction of tissues. Autoimmune diseases can be systemic or can affect specific organs or body systems. For most autoimmune diseases there is a clear sex difference in prevalence, whereby females are generally more frequently affected than males. In this review, we consider gender differences in systemic and organ-specific autoimmune diseases, and we summarize human data that outlines the prevalence of common autoimmune diseases specific to adult males and females in countries commonly surveyed. We discuss possible mechanisms for sex specific differences including gender differences in immune response and organ vulnerability, reproductive capacity including pregnancy, sex hormones, genetic predisposition, parental inheritance, and epigenetics. Evidence demonstrates that gender has a significant influence on the development of autoimmune disease. Thus, considerations of gender should be at the forefront of all studies that attempt to define mechanisms that underpin autoimmune disease.