Influence of forkhead box protein 3 polymorphisms (rs2232365, rs3761548) with the outcome of pregnancy: A meta-analysis

The role of microRNA-142a in Toxoplasma gondii infection-induced downregulation of Foxp3: implications for adverse pregnancy outcomes

BACKGROUND

Toxoplasma gondii (T. gondii) is capable of infecting nearly all warm-blooded animals and approximately 30% of the global population. Though most infections are subclinical in immunocompetent individuals, congenital contraction can lead to severe consequences such as spontaneous abortion, stillbirth, and a range of cranio-cerebral and/or ocular abnormalities. Previous studies reported that T. gondii-infected pregnancy mice unveiled a deficit in both the amount and suppressive functions of regulatory T (Treg) cells, accompanied with reduced levels of forkhead box p3 (Foxp3). Recently, accumulative studies have demonstrated that microRNAs (miRNAs) are, to some extent, relevant to T. gondii infection. However, the link between alterations in miRNAs and downregulation of Foxp3 triggered by T. gondii has been only sporadically studied.

METHODS

Quantitative reverse transcription polymerase chain reaction (RT-qPCR), protein blotting and immunofluorescence were employed to evaluate the impact of T. gondii infection and antigens on miRNA transcription and Foxp3 expression. Dual-luciferase reporter gene assays were performed to examine the fluorescence activity in EL4 cells, which were transfected with recombinant plasmids containing full-length/truncated/mutant microRNA-142a-3p (miR-142a) promoter sequence or wild type/mutant of Foxp3 3' untranslated region (3' UTR).

RESULTS

We found a pronounced increase in miR-142a transcription, concurrent with a decrease in Foxp3 expression in T. gondii-infected mouse placental tissue. Similarly, comparable findings have been experimentally confirmed through the treatment of EL4 cells with T. gondii antigens (TgAg) in vitro. Simultaneously, miR-142a mimics attenuated Foxp3 expression, whereas its inhibitors markedly augmented Foxp3 expression. miR-142a promoter activity was elevated upon the stimulation of T. gondii antigens, which mitigated co-transfection of mutant miR-142a promoter lacking P53 target sites. miR-142a mimics deceased the fluorescence activity of Foxp3 3' untranslated region (3' UTR), but it did not affect the fluorescence activity upon the co-transfection of mutant Foxp3 3' UTR lacking miR-142a target site.

CONCLUSION

In both in vivo and in vitro studies, a negative correlation was discovered between Foxp3 expression and miR-142a transcription. TgAg enhanced miR-142a promoter activity to facilitate miR-142a transcription through a P53-dependent mechanism. Furthermore, miR-142a directly targeted Foxp3 3' UTR, resulting in the downregulation of Foxp3 expression. Therefore, harnessing miR-142a may be a possible therapeutic approach for adverse pregnancy caused by immune imbalances, particularly those induced by T. gondii infection.

Meta-analysis of FOXP3 polymorphisms and recurrent spontaneous abortion susceptibility

BACKGROUND

The polymorphisms of the FOXP3 gene may mediate abnormalities in Tregs, leading to an imbalance in maternal-fetal immune tolerance and ultimately resulting in recurrent spontaneous abortion (RSA). This meta-analysis aims to assess the potential association between FOXP3 polymorphisms and susceptibility to RSA using five specific single nucleotide polymorphisms (SNPs).

MATERIALS AND METHODS

By conducting a comprehensive search across databases such as EMBASE, PubMed, Web of Science, Cochrane Library, CNKI, Wanfang, and CBM, we identified suitable studies for inclusion in the meta-analysis. The data extracted from these studies were subjected to analysis using Stata SE 15. To assess the degree of association, we utilized the odds ratio (OR) along with its corresponding 95% confidence intervals (CI). Five specific single nucleotide polymorphisms (SNPs) were employed in assessing the connection between FOXP3 gene polymorphisms and RSA.

RESULTS

The meta-analysis demonstrated a significant association between several polymorphisms (rs3761548, rs2232365, rs2232368, rs2280883, and rs2294021) and susceptibility to RSA. Conversely, the FOXP3 rs5902434 polymorphism was not associated with susceptibility to RSA.

CONCLUSION

Our meta-analysis suggests that these genetic variations within the FOXP3 gene might play a role in the progression of RSA disease. Meanwhile, large-scale studies that consider multiple factors are needed to validate this finding.

Influence of forkhead box protein 3 gene polymorphisms in recurrent pregnancy loss: A meta-analysis

BACKGROUND

Treg cells play an important role in development of tolerance in maternal immune system against the semi-allogenic embryo. Human forkhead box protein 3 (FOXP3) gene, is the major transcription factor responsible for the regulation of Treg function during pregnancy. Single nucleotide polymorphisms (SNPs) of FOXP3 gene have been reported as a risk factor for Recurrent Pregnancy Loss (RPL), however, results from previous studies are inconsistent.

METHODOLOGY

We have collected data from different studies to investigate the overall association of FOXP3 SNPs with risk of RPL. PubMed, Google Scholar, Elsevier, and Cochrane databases were searched to identify eligible studies. Odds Ratio (OR) and 95 % Confidence Interval (CI), calculated via fixed effect or random effect models, were used to evaluate strength of association. This meta-analysis included 11 studies (1383 RPL cases and 1413 controls) of 6 SNPs: rs3761548 A/C, rs2232365 A/G, rs2294021 T/C, 2280883 T/C, rs5902434del/ATT and rs141704699C/T, with ≥2 studies per SNPs and at least 1 significant result.

RESULTS

We observed that FOXP3 polymorphism was predominantly present in Asian women with history of RPL. rs2232365 A/G, rs3761548 A/C, rs2294021 T/C, rs2280883 T/C and rs5902434del/ATT polymorphisms were significantly associated with risk of RPL in Indian population. Further, among the most commonly seen polymorphism, rs3761548 A/C was significantly associated with risk of RPL in women from Kazakhstan, China and Gaza, Palestine; rs2232365 A/G in populations of Kazakhstan, Egypt, Iran and Gaza, Palestine. Results of this study indicates that FOXP3 polymorphism is significantly associated with risk of RPL, especially in Asians.

Association of IL-17 and IL-27 polymorphisms with susceptibility to recurrent pregnancy loss and pre-eclampsia: A systematic review and meta-analysis

OBJECTIVE

Recurrent pregnancy loss (RPL) and pre-eclampsia (PE) are immune-related pregnancy complications that have been linked to CD4+ T cells and their cytokines, which can be influenced by genetic polymorphisms. This meta-analysis aimed to investigate the relationship between interleukin (IL)-17 and -27 polymorphisms and the susceptibility to RPL and PE.

METHODS

All eligible case-control studies published up to February 2023 were identified by searching PubMed, EMBASE, Cochrane, Web of Science, and Google Scholar. The risk of recurrent pregnancy loss and PE associated with the IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were estimated for each study.

RESULTS

The meta-analysis incorporated a total of 13 studies. The overall analysis indicated that IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with immune-related pregnancy complications, including RPL and PE. However, when the analysis was stratified by disease type, the IL-17 rs2275913 polymorphism was found to be associated with an increased risk of RPL (recessive model AA/GA + GG: OR = 1.68, 95% confidence interval [CI]: 1.13-2.49, p = .01).

CONCLUSIONS

The IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with RPL and PE, whereas the IL-17 rs2275913 polymorphism was associated with the susceptibility to recurrent miscarriage.

Genetic association study of intron variants in the forkhead box protein P3 gene in Chinese patients diagnosed with cervical cancer

The aim of this study was to investigate the effects of forkhead box protein P3 (FOXP3) intron single nucleotide variants (SNVs) in high-risk human papilloma virus (HR-HPV) infection and cervical cancer (CC) malignant lesions. We performed FOXP3 genotyping in 350 patients with CC and 350 healthy controls using the ImLDR multiple single nucleotide polymorphism genotyping technology. The heterozygous mutation TC in rs2294021 decreased the risk of HR-HPV infection and CC malignant lesions (TC vs. TT: OR = 0.71, 95% CI = 0.51-0.99); the dominant model TC+CC and allele C in rs2294021 decreased the risk of CC malignant lesions (TC+CC vs. TT: OR = 0.69, 95% CI = 0.50-0.95; C vs. T: OR = 0.78, 95% CI = 0.63-0.97). The heterozygous mutation GA, dominant model GA+AA and allele A in rs3761549 also decreased the risk of HR-HPV infection and CC malignant lesions (GA vs. GG: OR = 0.70, 95% CI = 0.51-0.96; GA+AA vs. GG: OR = 0.69, 95% CI = 0.51-0.94; A vs. G: OR = 0.75, 95% CI = 0.58-0.96). Patients with CC and HR-HPV infection carrying rs2294021 TC and rs3761549 GA had lower expression of FOXP3 protein. Haplotype analysis revealed that T-C-A decreased the risk of HR-HPV infection. Furthermore, we found a significant association between immune cells infiltration and prognosis in patients with CC. Our findings demonstrated that rs2294021 and rs3761549 variants may protect against HR-HPV and CC malignant lesions by downregulating FOXP3 and that FOXP3 was associated with immune cells infiltration, which affected the prognosis of CC.

Human forkhead box protein 3 gene variants associated with altered susceptibility to idiopathic recurrent pregnancy loss: A retrospective case-control study

BACKGROUND

The pathogenesis of recurrent pregnancy loss (RPL) is multifactorial and not completely elucidated. Dysregulated immunity was implicated with RPL, in which regulatory T cells (Tregs) are key. As Tregs development and function are regulated by forkhead box P3 (FOXP3) transcription factor, and as FOXP3 expression is genetically determined, a role for FOXP3 polymorphisms in RPL pathogenesis was suggested.

AIM

To investigate the association of rs2294021, rs2232365, rs3761548, and rs141704699 FOXP3 variants with idiopathic RPL in Lebanese women.

METHODS

This retrospective case-control study included 386 RPL cases and 398 age-matched control women. Logistic odds ratios (OR) were estimated with 95% confidence interval after adjustment; a significance value of P<.05 was set.

RESULTS

Significantly lower rs22944021 and rs2232365 minor allele frequency (MAF) was found in patients with idiopathic RPL in comparison with the control group. Furthermore, statistically significantly lower frequency of heterozygous and homozygous rs2294021 and rs2232365 genotypes was seen in controls, while significantly lower rs3761548 heterozygous genotype frequencies were found in the patient group. Obesity, antihypertension treatment, smoking, positive RPL family history, abortion state, and infertility treatment correlated negatively with rs2294021, while rs2232365 negatively correlated with obesity, and rs3761548 negatively correlated with infertility treatment. Marked linkage disequilibrium (LD) was noted among FOXP3 SNPs, with TGCC and CGAC haplotypes being positive, while CAAC, CACC, and TGAC haplotypes being negatively associated with RPL risk. Except for CGAC, the association of these haplotypes with RPL persisted after adjustment.

CONCLUSION

FOXP3 gene variants and haplotypes are associated with altered incidence of RPL, proposing the role of Treg in RPL pathogenesis.

Associations of FOXP3 gene polymorphisms with susceptibility and severity of preeclampsia: A meta-analysis

OBJECTIVE

FOXP3 single nucleotide polymorphisms (SNPs) were recently elucidated to influence the development of preeclampsia (PE), but the results on this issue still remained controversial. Thus, a meta-analysis was implemented to systematically investigate the roles of FOXP3 SNPs in PE.

METHODS

Eligible publications were identified by retrieving relevant electronic databases. Meanwhile, the association intensity was estimated by calculating odds ratios (ORs) and 95% confidence intervals (CIs) in various genetic models.

RESULTS

Totally eight investigations involving 3446 subjects were enrolled in the final meta-analysis. The AC and AC + CC genotypes of FOXP3 rs3761548 were related to the susceptibility of PE in over-dominant (OR = 1.19, 95%CI = 1.02-1.38, P = 0.03) and recessive (OR = 0.59, 95% CI: 0.36-0.97, P = 0.04) models. Furthermore, correlation between rs2232365 and PE was observed in recessive model (GG vs. GA + AA) (OR = 0.79, 95%CI: 0.65-0.97, P = 0.03). Moreover, rs2232365 GA and GG + GA genotypes were associated with the severity of PE. However, rs4824747, rs3761547 and rs2280883 polymorphisms had no significant impact on PE susceptibility.

CONCLUSIONS

FOXP3 rs3761548 and rs2232365 SNPs influenced the PE susceptibility and therefore may be potential biomarkers for prediction of PE risk.

Association of Human forkhead box protein 3 (FOXP3) gene polymorphisms with idiopathic recurrent pregnancy loss among Kazakhstani women

BACKGROUND

Recurrent pregnancy loss (RPL) is major pregnancy complication, with poorly defined cause.Forkhead Box P3 (FOXP3) is a transcription factor that supports Treg activation and development and attenuates immune responses. As FOXP3 production is genetically determined, we tested the association of FOXP3 gene variants with RPL.

METHODS

A retrospective case-control study, performed between April 2019 and February 2020. Study subjects comprised 62 RPL cases and 60 control women. Genotyping of the four FOXP3 variants rs2294021 (T > C), rs2232365 (G > A), rs3761548 (C > A), and rs141704699 (C > T) was done by real-time PCR, with defined clusters. Logistic odds ratios (ORs) of RPL risk were estimated with 95% confidence interval (CI) after adjustment; statistical significance set at P < 0.05.

RESULTS

Minor allele frequency (MAF) of rs2294021 was significantly lower [P < 0.001; OR(95% CI) = 0.25(0.11-0.55)], while rs2232365 MAF was significantly higher [P = 0.045; OR(95% CI) = 1.85(1.05-3.28)] in cases, hence assigning RPL-protection and -susceptibility to these variants, respectively. Increased RPL risk was seen in rs2232365 homozygous minor allele carrying genotype [OR(95% CI) = 5.14(1.01-26.15)], while reduced RPL risk was noted in rs2294021 heterozygous [OR(95% CI) = 0.30(0.11-0.80)], and homozygous minor allele [OR(95% CI) = 0.10(0.01-0.83)] genotype carriers. Moderate linkage disequilibrium analysis was seen between the tested variants. Increased frequency of TACC, and reduced frequency of CGAC haplotypes were seen in RPL cases when compared to controls, thereby assigning RPL susceptibility and protection to these haplotypes, respectively.

CONCLUSION

These results suggest that FOXP3 variants and haplotypes are associated with idiopathic RPL, suggesting the likely contribution of Treg to RPL.

The role of decidual regulatory T cells in the induction and maintenance of fetal antigen-specific tolerance: Imbalance between regulatory and cytotoxic T cells in pregnancy complications

Fetal antigen-specific tolerance is important for maintaining allogeneic pregnancies. Maternal conventional T cells recognize fetal antigens; however, regulatory T (Treg) cells suppress immune reactions against the fetus. Fetal antigen-specific Treg cells are induced in the decidua upon contact with antigen-presenting cells and extravillous trophoblasts (EVTs). Functional alteration of cytotoxic T cells (CTLs) in the decidua also contributes to maintaining the pregnancy. Reduced, dysfunctional, and imbalanced Treg cell distribution likely contributes to the pathogenesis of pregnancy complications, such as miscarriage and preeclampsia. Recent studies have revealed differences in Treg cell characteristics during preeclampsia and miscarriage. Treg cell reduction in the decidua is likely associated with miscarriage. Insufficient expansion of fetal antigen-specific Treg cells in the decidua probably plays a role in preeclampsia pathogenesis. In addition, the balance between Treg cell-mediated tolerance and functional alteration of CTLs is important. Further investigations of functional molecules in Treg cells will contribute to the development of immunotherapy for pregnancy complications.

Novel association between FOXO3 rs2232365 polymorphism and late-onset preeclampsia: a case-control candidate genetic study

BACKGROUND

Both genetic susceptibility and dysregulated lipid metabolism are important susceptibilities to preeclampsia. In the study, we devote to investigate the associations of FOXO3 and TLR7 genetic polymorphisms with preeclampsia in a Chinese population.

METHODS

This case-control study involved 335 Han Chinese pregnant women, including 177 pregnant women with preeclampsia and 158 healthy controls. The preeclampsia group was further sub-grouped into early-onset preeclampsia (EOPE, n = 70)and late-onset preeclampsia (LOPE, n = 107. Three single nucleotide polymorphisms (SNPs), including FOXO3 (rs2232365, rs3761548), and TLR7 rs3853839 were genotyped by multiplex PCR for targeted next-generation sequencing. The χ2 test and multiple interaction effect analyses were performed to determine the association of three SNPs with serum lipid levels and thyroid function in women with preeclampsia.

RESULTS

The genotype (CC vs. TT + CT) distribution of rs2232365 revealed a significant association with LOPE (P = 0.004, odds ratio = 3.525 (0.95 CI: 1.498-8.164)). No significant difference was found in the genotype and allele frequencies of rs3761548 and rs3853839 between controls and cases (P > 0.05). Moreover, the genotype CT/TT of rs2232365 was significantly correlated with increased TG/HDL levels in the LOPE group (p = 0.014).

CONCLUSIONS

The polymorphisms of rs2232365 are associated with the risk of LOPE and may modulate TG/HDL levels in pregnant women with LOPE.

Analysis of the frequency of type 2 innate lymphoid cells and regulatory T cells in abortion-prone mice

Recurrent spontaneous abortion (RSA) is the most common pregnancy related complication, affecting 1-5 % of pregnancies. Despite hormonal, genetic and anatomical factors that result in abortion, impairment of immune response at the feto-maternal interface during the first trimester of pregnancy is also one of the main causes of RSA. In the present study, we evaluated the frequency of blood and uterine group 2 innate lymphoid cells (ILC2s), their subsets and regulatory T cells (Tregs) in CBA/J × DBA/2 J as an abortion-prone model compared to normal pregnant (NP) mice using immunophenotyping. Results indicated that the percentages of ILC2s were significantly decreased in the AP group compared to the NP group at mid-gestation (P ≤ 0.01). Moreover, the percentages of both blood and uterine nILC2s were increased in NP mice at mid-gestation (P ≤ 0.01, and P ≤ 0.05, respectively), while iILC2s significantly increased in AP mice at mid-gestation (P ≤ 0.01, and P ≤ 0.05, respectively). Tregs were reduced in AP mice at both early and mid-gestation stages (P ≤ 0.01). Overall, our findings suggest that the changes in blood and uterine ILC2s might be associated with abortion in mice.

MDSCs in pregnancy: Critical players for a balanced immune system at the feto-maternal interface

Myeloid-derived suppressor cells (MDSCs) have emerged as a new immune regulator at the feto-maternal interface. Although the phenotypes and functions of these cells were primarily studied in pathological conditions such as cancers and infections, new evidence has underscored their beneficial roles in homeostasis and physiological circumstances such as normal pregnancy. In this regard, studies have shown an increased number of MDSCs, particularly granulocytic MDSCs, at the feto-maternal interface. These cells participate in maintaining immunological tolerance between mother and semi-allograft fetus through various mechanisms. They further seem to play critical roles in placentation and fetus growth process. The absence or dysregulation of MDSCs during pregnancy have been reported in several pregnancy complications. These cells are also abundant in the cord blood of neonates so as to balance the immune responses and prevent aggressive inflammatory responses. The current review summarizes and organizes detailed data on MDSCs and their roles during pregnancy.