STAT4 single nucleotide gene polymorphisms and susceptibility to endometriosis-related infertility

Association of endometriosis with Sjögren's syndrome: Genetic insights (Review)

Patients with a history of endometriosis have an increased risk of developing various autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and celiac disease. There is a potential association between endometriosis and an increased susceptibility for Sjögren's syndrome (SS). SS is a common chronic, inflammatory, systemic, autoimmune, multifactorial disease of complex pathology, with genetic, epigenetic and environmental factors contributing to the development of this condition. It occurs in 0.5‑1% of the population, is characterized by the presence of ocular dryness, lymphocytic infiltrations and contributes to neurological, gastrointestinal, vascular and dermatological manifestations. Endometriosis is an inflammatory, estrogen‑dependent, multifactorial, heterogeneous gynecological disease, affecting ≤10% of reproductive‑age women. It is characterized by the occurrence of endometrial tissue outside the uterine cavity, mainly in the pelvic cavity, and is associated with pelvic pain, dysmenorrhea, deep dyspareunia and either subfertility or infertility. It is still unclear whether SS appears as a secondary response to endometriosis, or it is developed due to any potential shared mechanisms of these conditions. The aim of the present review was to explore further the biological basis only of the co‑occurrence of these disorders but not their association at clinical basis, focusing on the analysis of the partially shared genetic background between endometriosis and SS, and the clarification of the possible similarities in the underlying pathogenetic mechanisms and the relevant molecular pathways.

Aberrant Hoxa10 gene methylation as a mechanism for endosulfan-induced implantation failures in rats

DNA methylation is a well-established epigenetic mechanism controlling gene expression. Environmental chemicals, such as pesticides have been shown to alter DNA methylation. We have previously shown that the insecticide endosulfan impairs female fertility in rats by increasing the rate of preimplantation embryo losses. In this study, we evaluated whether early postnatal exposure to endosulfan affects long-term transcriptional regulation of Homeobox A10 (Hoxa10) gene, which is a key marker of endometrial receptivity. Female rats were neonatally exposed to 6 or 600 μg/kg/day (ENDO6 and ENDO600, respectively) of endosulfan and uterine samples collected on gestational day (GD) 5. Hoxa10 protein and mRNA levels were assessed by immunohistochemistry and quantitative real-time PCR (qRT-PCR), respectively. In silico analysis of enzyme-specific restriction sites and predicted transcription factors were performed to investigate the methylation status of the regulatory regions of Hoxa10 gene by methylation-sensitive restriction enzymes-PCR technique. The expression of the DNA methyltransferases (Dnmts) was also evaluated. ENDO600 showed a decreased uterine Hoxa10 expression at protein and transcript level, while ENDO6 decreased only the level of transcripts, during the receptive stage. In addition, endosulfan increased levels of Dnmt3a and Dnmt3b. Dysregulation of DNA methylation patterns of Hoxa10 regulatory regions was detected in ENDO6- and ENDO600-treated rats. All these results suggest that aberrant DNA methylation in Hoxa10 gene could be an underlining mechanism contributing to explain endosulfan-induced preimplantation losses.

Genetic Polymorphisms in Genes Involved in the Type I Interferon System (IFIH1/MDA-5, TNFAIP3/A20, and STAT4): Association with SLE Risk in Egyptian Children and Adolescents

Purpose

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune inflammatory disease that is influenced by both genetic and environmental factors and associated with dysregulation of type I interferon (INF) response. This study aimed to investigate the effects of single nucleotide polymorphisms (SNPs) of the IFIH1, TNFAIP3, and STAT4 genes in the type I INF system on SLE risk in Egyptian children and adolescents.

Patients and Methods

We recruited 94 SLE individuals and 94 healthy subjects. SNPs of IFIH1 rs3747517 C/T, TNFAIP3 rs610604 G/T, and STAT4 rs7574865 G/T were evaluated using TaqMan™ SNP genotyping assay.

Results

Individuals with the TT, CT+TT genotypes, and T allele of rs3747517 in the IFIH1 gene were protective for SLE patients (OR = 0.429, 95% CI = 0.191-0.962, P = 0.040), (OR = 0.685, 95% CI = 0.477-0.984, P = 0.041), and (OR = 0.705, 95% CI = 0.527-0.944, P = 0.019), respectively. Also, individuals with the TT, GT+TT genotypes, and T allele of rs7574865 in the STAT4 gene were associated with SLE risk (OR = 3.945, 95% CI = 1.303-11.947, P = 0.015), (OR = 1.536, 95% CI = 1.058-2.231, P = 0.024), and (OR = 1.522, 95% CI = 1.113-2.082, P = 0.009), respectively. In the case of TNFAIP3 rs610604, no significant association of genotypes or alleles with SLE were detected, while the three SNPs did not show any significant association with the SLE clinical or laboratory features.

Conclusion

Our findings indicated that rs3747517 in IFIH1 was protective for SLE in Egyptian children and adolescents. Moreover, rs7574865 in STAT4 not rs610604 in TNFAIP3 was associated with SLE risk.

Genomics of Endometriosis: From Genome Wide Association Studies to Exome Sequencing

This review aims at better understanding the genetics of endometriosis. Endometriosis is a frequent feminine disease, affecting up to 10% of women, and characterized by pain and infertility. In the most accepted hypothesis, endometriosis is caused by the implantation of uterine tissue at ectopic abdominal places, originating from retrograde menses. Despite the obvious genetic complexity of the disease, analysis of sibs has allowed heritability estimation of endometriosis at ~50%. From 2010, large Genome Wide Association Studies (GWAS), aimed at identifying the genes and loci underlying this genetic determinism. Some of these loci were confirmed in other populations and replication studies, some new loci were also found through meta-analyses using pooled samples. For two loci on chromosomes 1 (near CCD42) and chromosome 9 (near CDKN2A), functional explanations of the SNP (Single Nucleotide Polymorphism) effects have been more thoroughly studied. While a handful of chromosome regions and genes have clearly been identified and statistically demonstrated as at-risk for the disease, only a small part of the heritability is explained (missing heritability). Some attempts of exome sequencing started to identify additional genes from families or populations, but are still scarce. The solution may reside inside a combined effort: increasing the size of the GWAS designs, better categorize the clinical forms of the disease before analyzing genome-wide polymorphisms, and generalizing exome sequencing ventures. We try here to provide a vision of what we have and what we should obtain to completely elucidate the genetics of this complex disease.

Identification and Analyzation of Differentially Expressed Transcription Factors in Endometriosis

Background: Endometriosis is interpreted as the existence of endometrium outside the uterine cavity, such as ovaries, fallopian tubes and pelvic cavity. Dysmenorrhea, abnormal menstruation, infertility, and chronic pelvic pain are the primary symptoms of endometriosis. Although there are many theories about the origin of endometriosis, the exact factor of the disease has not been confirmed. Therefore, many other mechanisms are still worth exploring. Materials and Methods: The gene lists of the transcription factors (TFs) were selected from the intersections of three databases. The limma R package was used to analyze the differentially expressed genes (DEGs) of GSE6364 and GSE7305 and the DEGs intersected with the TFs to obtain the differentially expressed TFs (DETFs). Subsequently, one-way ANOVA and Student's t-test were used to analyze the expression of DETFs in different phases of the endometrium and the endometrium of the infertile and fertile females with endometriosis, respectively. Enrichment analysis and PPI network were performed to reveal the molecular mechanisms of endometriosis. Finally, the plotROC R package was used to evaluate the sensitivity and specificity of hub TFs for the diagnosis of endometriosis. Results: A total of 54 DETFs were screened out in endometriosis. The expression of up-regulated DETFs was gradually increased from the early secretory to the proliferative phase of the endometrium. Most up-regulated DETFs increased expression in the endometrium of infertile females. The pathways of DETFs were mainly enriched in stem cell differentiation, transcription activity, steroid hormone receptor activity and herpes simplex virus. Two hub TFs (RUNX2 and BATF) and two sub-networks were finally acquired from the PPI network. RUNX2 and BATF also had high diagnostic value in endometriosis. Conclusion: We discovered and analyzed 54 DETFs that were closely related to endometriosis, which would contribute to explore new mechanisms of endometriosis and search for new diagnostic markers and effective therapeutic targets.

Peritoneal Fluid Cytokines Reveal New Insights of Endometriosis Subphenotypes

Endometriosis is a common inflammatory gynecological disorder which causes pelvic scarring, pain, and infertility, characterized by the implantation of endometrial-like lesions outside the uterus. The peritoneum, ovaries, and deep soft tissues are the commonly involved sites, and endometriotic lesions can be classified into three subphenotypes: superficial peritoneal endometriosis (PE), ovarian endometrioma (OE), and deep infiltrating endometriosis (DIE). In 132 women diagnosed laparoscopically with and without endometriosis (n = 73, 59 respectively), and stratified into PE, OE, and DIE, peritoneal fluids (PF) were characterized for 48 cytokines by using multiplex immunoassays. Partial-least-squares-regression analysis revealed distinct subphenotype cytokine signatures—a six-cytokine signature distinguishing PE from OE, a seven-cytokine signature distinguishing OE from DIE, and a six-cytokine-signature distinguishing PE from DIE—each associated with different patterns of biological processes, signaling events, and immunology. These signatures describe endometriosis better than disease stages (p < 0.0001). Pathway analysis revealed the association of ERK1 and 2, AKT, MAPK, and STAT4 linked to angiogenesis, cell proliferation, migration, and inflammation in the subphenotypes. These data shed new insights on the pathophysiology of endometriosis subphenotypes, with the potential to exploit the cytokine signatures to stratify endometriosis patients for targeted therapies and biomarker discovery.

STAT4: an immunoregulator contributing to diverse human diseases

Signal transducer and activator of transcription 4 (STAT4) is a member of the STAT family and localizes to the cytoplasm. STAT4 is phosphorylated after a variety of cytokines bind to the membrane, and then dimerized STAT4 translocates to the nucleus to regulate gene expression. We reviewed the essential role played by STAT4 in a wide variety of cells and the pathogenesis of diverse human diseases, especially many kinds of autoimmune and inflammatory diseases, via activation by different cytokines through the Janus kinase (JAK)-STAT signaling pathway.

Influence of STAT4 gene polymorphisms in the pathogenesis of endometriosis

The STAT4 gene is vital to signaling pathways in the immune response. Immunological alterations are involved in the pathogenesis of endometriosis, and STAT4 polymorphisms may be linked to disease development. This study's aim is to evaluate the possible association between four STAT4 polymorphisms (rs7601754/G > A, rs11889341/C > T, rs7574865/T > G, and rs7582694/C > G) and the pathogenesis of endometriosis in Brazilian women. This case-control study's sample comprised 238 women with endometriosis and 201 healthy, fertile women without endometriosis (which was surgically confirmed). Genotyping was performed using the TaqMan system with a real-time polymerase chain reaction; the genotype, allele, and haplotype frequencies were then compared between groups. A single-polymorphism analysis revealed that the TT genotype of the rs7574865/T > G polymorphism was significantly more frequent in women with minimal or mild endometriosis than in the controls (10% vs. 5%, p = 0.047). The CGAC, GTAT, and GTAC haplotypes were significantly more frequent in the women with endometriosis-related infertility (5.8%, 4.1%, and 2.9%, respectively) than in the controls (2.4%, 1.1%, and 0.8%, respectively; p = 0.020, p = 0.011, and p = 0.032, respectively), but the GGGC and CTAT haplotypes were significantly more prevalent in the control group (34.7% and 13.9%, respectively) than among the infertile group (26.2% and 9.1%, respectively). In addition, the CGAC haplotype was more frequently found in those with minimal or mild endometriosis (6.8%) than in the controls (2.4%, p = 0.009), and the GTAT haplotype was more commonly found in those with moderate or severe disease (3.6%) than in the controls (1.1%, p = 0.028). These findings suggest that STAT4 polymorphisms can influence the pathogenesis of endometriosis.

Endometriosis and in vitro fertilisation

The aim of the present review was to discuss a matter of concern in the clinical field of obstetrics/gynecology, namely the potency of in vitro fertilization (IVF) in the management of endometriosis-associated infertility. Endometriosis is a medical condition affecting one tenth of women in their fertile years, and accounts for up to 50% of infertile women. Thus, such high prevalence has established the necessity for investigating the effectiveness of available techniques in eradicating the disease and constraining infertility as well as the accompanying pain symptoms of endometriosis. The underlying mechanisms connecting endometriosis with low fecundity have been extensively studied, both in terms of genetic alterations and epigenetic events that contribute to the manifestation of an infertility phenotype in women with the disease. Several studies have dealt with the impact of IVF in pregnancy rates (PRs) on patients with endometriosis, particularly regarding women who wish to conceive. Results retrieved from studies and meta-analyses depict a diverse pattern of IVF success, underlining the involvement of individual parameters in the configuration of the final outcome. The ultimate decision on undergoing IVF treatment should be based on objective criteria and clinicians' experience, customized according to patients' individual needs.

Involvement of Interferon Regulatory Factor 5 (IRF5) Gene Polymorphisms and Haplotype in Endometriosis-related Infertility

Introduction

The IRF5 gene belongs to a family of transcription factors involved in modulating cell growth, differentiation, apoptosis, and immune system activity. A growing body of evidence indicates that immunological alterations are involved in the pathogenesis of endometriosis, and as a result, polymorphisms in autoimmune-related genes have emerged as possible candidates linked to disease development. Here, we aimed to evaluate a possible association between IRF5 polymorphisms (rs2004640/T>G, rs3807306/G>T, rs10488631/T>C and rs2280714/T>C) and the pathogenesis of endometriosis.

Methods

A case-control study was performed comprising an experimental group of 236 infertile women with endometriosis and a control group of 232 fertile women. IRF5 polymorphisms were identified by real-time PCR using the TaqMan method. Genotype distribution and allele frequency were calculated, and haplotype analysis was performed.

Results

Single-marker analysis revealed that the IRF5 rs10488631 (polymorphic C allele) polymorphism was significantly associated with moderate/severe endometriosis (p = 0.028; OR = 1.79, 95% IC = 1.09–2.94). No association was found with respect to rs2004640, rs3807306 and rs2280714 polymorphisms and the endometriosis group. The combined genotypes of four IRF5 polymorphisms identified the haplotype “GGTT”, which was associated with protection against minimal/mild endometriosis-related infertility (p = 0.003), while the haplotype “GTCT” was associated with a risk of developing moderate/severe endometriosis-related infertility (p = 0.047).

Conclusions

This is the first study to report an association between IRF5 polymorphisms and endometriosis, and the findings suggest that the IRF5 rs10488631 polymorphism and haplotype “GTCT” were involved in the risk of moderate/severe endometriosis development. The haplotype “GGTT” was associated with protection against minimal/mild endometriosis.

Lack of Association between STAT4 Single Nucleotide Polymorphisms and Iranian Juvenile Rheumatoid Arthritis Patients

Juvenile rheumatoid arthritis (JRA) is a common chronic systemic autoimmune disease in children. Single nucleotide polymorphisms (SNPs) of signal transducer and activator of transcription 4 (STAT4) gene are suspected to have association with the risk of autoimmune diseases. Previous investigations have indicated that the STAT4 rs7574865 T allele was significantly associated with rheumatoid arthritis. In this study, we aimed to evaluate the association of STAT4 SNPs with JRA in Iranian population. T allele of STAT4 rs7574865 SNP was less frequent in patients than in controls, and the difference was not significant (p = 0.19, OR = 0.72, 95% CI: 0.44 -1.17). In addition, G allele of this SNP was frequent but not significant in JRA patients (p = 0.19, OR = 1.38, 95% CI: 0.85-2.25). Neither alleles nor genotypes of rs7601754 SNP of STAT4 gene demonstrated associations with JRA. We recognize that gene variants of STAT4 did not affect JRA susceptibility in Iranian population.