Higher frequency of circulating, but not tissue regulatory T cells in patients with endometriosis

Causality of immune cells and endometriosis: a bidirectional mendelian randomization study

BACKGROUND

Endometriosis, a prevalent chronic condition, afflicts approximately 10% of women in their reproductive years. Emerging evidence implicates immune cells in the pathogenesis of endometriosis, particularly in angiogenesis, tissue proliferation, and lesion invasion. This investigation employs two-sample Mendelian Randomization (MR) to dissect the bidirectional causal relationships between immune cell profiles and endometriosis.

METHODS

We leveraged publicly available genome-wide association study (GWAS) data to elucidate the causal interplay between immune cell traits and endometriosis. Utilizing GWAS summary statistics ranging from accession numbers GCST90001391 to GCST90002121 and endometriosis data from the FinnGen study GWAS (8,288 endometriosis cases and 68,969 controls), we adopted stringent criteria for instrumental variable selection. We applied MR-Egger, weighted median, inverse variance weighted (IVW), and weighted mode methods to derive causal estimates. To address potential heterogeneity and pleiotropy, Cochran's Q test, MR-Egger intercept, and leave-one-out analyses were executed. Reverse-direction MR and bidirectional MR analyses evaluated potential reciprocal causation and the influence of endometriosis on immune cell composition.

RESULTS

Our analysis identified five immune phenotypes inversely associated with endometriosis risk. These phenotypes comprise: a percentage of CD11c + HLA-DR + + monocytes, CD25 expression on CD39 + CD4 + T cells, elevated CD25 on CD45RA + CD4 + non-regulatory T cells, HLA-DR intensity on HLA-DR + CD8 bright (CD8br) T cells, and the proportion of naïve double-negative (CD4 - CD8- %DN) T cells. In contrast, eleven phenotypes were positively correlated with endometriosis risk, including: CD127 expression on T cells, the proportion of CD24 + CD27 + B cells within lymphocytes, CD25 expression on CD28 + CD4 + T cells, CD28 expression on CD39 + activated regulatory T cells (activated Tregs), the frequency of bright CD33 HLA-DR + CD14 - cells within the CD33br HLA-DR + compartment, CD45 expression on lymphocytes and natural killer (NK) cells, activation status of central memory CD8 bright (CM CD8br) T cells, CX3CR1 expression on monocytes, and the percentage of HLA-DR + NK cells within the NK cell subset. Sensitivity assessments that excluded significant heterogeneity and pleiotropy confirmed the stability of these associations, thereby reinforcing the validity of our findings.

CONCLUSION

This study provides novel evidence of the potential causal impact of specific immune cells on the risk of developing endometriosis. These findings enhance our understanding of endometriosis pathophysiology and may inform innovative approaches for its diagnosis and management. While our findings provide novel insights, limitations such as potential horizontal pleiotropy and reliance on European ancestry data should be considered. Future research should expand to diverse populations and incorporate individual-level data to refine these findings.

Foxp3+CD39+CD73+ regulatory T-cells are decreased in the peripheral blood of women with deep infiltrating endometriosis

Endometriosis's pathophysiology remains incompletely understood, with evidence pointing towards a dysregulated immune response. Regulatory T (Treg) cells, pivotal in maintaining self-tolerance, may facilitate the survival of ectopic endometrial cells within the abdominal cavity, thereby contributing to endometriosis development. This study aimed to assess the prevalence of CD39+CD73+ suppressor Treg cell subsets in the peripheral blood of endometriosis patients. This research focuses on the pivotal role of regulatory T-cells (Tregs), which are essential for maintaining immune tolerance and preventing autoimmune diseases. A case-control study was conducted, including 32 women diagnosed with endometriosis and 22 control subjects. The frequency of peripheral blood CD39+CD73+ suppressor Treg cells was quantified using flow cytometry. No significant differences were observed in the frequency of CD3+CD4+CD25High cells (Median [M]: 10.1; Interquartile Range [IQR]: 6.32‒18.3 vs. M: 9.72; IQR: 6.22-19.8) or CD3+CD4+CD25HighCD39+Foxp3+ cells (M: 31.1; IQR: 19.7-44.0 vs. M: 30.55; IQR: 18.5-45.5) between controls and patients. However, a significantly lower frequency of CD3+CD4+CD25HighCD39+CD73+ cells was observed in the endometriosis group compared to controls (M: 1.98; IQR: 0.0377-3.17 vs. M: 2.25; IQR: 0.50-4.08; p = 0.0483), suggesting a reduction in systemic immune tolerance among these patients. This finding highlights the potential role of CD39 and CD73 expression on Treg cells as biomarkers for assessing disease severity and progression. Furthermore, elucidating the mechanisms driving these alterations may unveil new therapeutic strategies to restore immune equilibrium and mitigate endometriosis symptoms.

Vitamin D and reproductive disorders: a comprehensive review with a focus on endometriosis

Vitamin D is a fat-soluble steroid hormone that was initially known only for regulating calcium and phosphorus levels and maintaining bone health. However, it was later discovered that many organs express vitamin D metabolizing enzymes and have a ligand for vitamin D, which regulates the expression of an extensive assortment of genes. As a result, vitamin D is indispensable for the proper function of organs, and its deficiency is believed to be a critical factor in symptoms and disorders such as cardiovascular diseases, autoimmune diseases, and cancers. The significance of vitamin D in reproductive tissues was recognized later, and studies have revealed its crucial role in male and female fertility, as well as proper reproductive function during pregnancy. Vitamin D deficiency has been identified as a risk factor for infertility, gonadal cancers, pregnancy complications, polycystic ovary syndrome, and endometriosis. However, data investigating the association between vitamin D levels and reproductive disorders, including endometriosis, have encountered inconsistencies. Therefore, the present study aims to review existing research on the effect of vitamin D on proper reproductive function, and the role of deficiency in reproductive diseases and specifically focuses on endometriosis.

ATG8 inhibited endometriosis formation by regulating Treg cells differentiation via integrin α4β1 and Talin-1 interaction

RESEARCH QUESTION

What is the relationship between ATG8 and integrin α4β1, Talin-1, and Treg cell differentiation, and the effects on endometriosis (EMS)?

DESIGN

First, the correlation between the ATG8, Talin-1, integrin α4β1, and differentiation of Treg cells and EMS was examined in clinical samples. Human peripheral blood mononuclear cells (PBMC) and endometrial stromal cells were extracted and identified, oe-ATG8 and oe-integrin α4β1 were transfected to overexpress ATG8 and integrin α4β1, and Tregs cell differentiation and endometrial stromal cells (ESC) function were detected. In addition, the molecular mechanism by which ATG8 inhibited EMS disease progression at the molecular and animal levels was investigated.

RESULTS

ATG8 expression was negatively correlated with positive proportion of Tregs cells (P = 0.0463). The expression of Talin-1 and integrin-α4β1 (both P < 0.0001) in PBMC decreased significantly after oe-ATG8 transfection, whereas the Treg cells' positive rate significantly increased (P = 0.0003). The ESC proliferation, adhesion, migration, and invasion (all P < 0.0001) declined after co-culture with Treg cells that underwent oe-ATG8 transfection. The expression of Talin-1 (P = 0.0025) and integrin-α4β1 (P = 0.0002) in PBMC increased significantly after oe-integrin α4β1 and oe-ATG8 transfection. In addition, this transfection reversed the corresponding regulation of oe-ATG8 transfection. Finally, animal experiments in vivo confirmed that ATG8 inhibited EMS disease progression.

CONCLUSION

The ATG8 regulated Treg cell differentiation and inhibited EMS formation by influencing the interaction between integrin α4β1 and Talin-1.

Identification and validation of risk score model based on gene set activity as a diagnostic biomarker for endometriosis

Objective

The enigmatic nature of Endometriosis (EMS) pathogenesis necessitates investigating alterations in signaling pathway activity to enhance our comprehension of the disease's characteristics.

Methods

Three published gene expression profiles (GSE11691, GSE25628, and GSE7305 datasets) were downloaded, and the "combat" algorithm was employed for batch correction, gene expression difference analysis, and pathway enrichment difference analysis. The protein-protein interaction (PPI) network was constructed to identify core genes, and the relative enrichment degree of gene sets was evaluated. The Lasso regression model identified candidate gene sets with diagnostic value, and a risk scoring diagnostic model was constructed for further validation on the GSE86534 and GSE5108 datasets. CIBERSORT was used to assess the composition of immune cells in EMS, and the correlation between EMS diagnostic value gene sets and immune cells was evaluated.

Results

A total of 568 differentially expressed genes were identified between eutopic and ectopic endometrium, with 10 core genes in the PPI network associated with cell cycle regulation. Inflammation-related pathways, including cytokine-receptor signaling and chemokine signaling pathways, were significantly more active in ectopic endometrium compared to eutopic endometrium. Diagnostic gene sets for EMS, such as homologous recombination, base excision repair, DNA replication, P53 signaling pathway, adherens junction, and SNARE interactions in vesicular transport, were identified. The risk score's area under the curve (AUC) was 0.854, as indicated by the receiver operating characteristic (ROC) curve, and the risk score's diagnostic value was validated by the validation cohort. Immune cell infiltration analysis revealed correlations between the risk score and Macrophages M2, Plasma cells, resting NK cells, activated NK cells, and regulatory T cells.

Conclusion

The risk scoring diagnostic model, based on pathway activity, demonstrates high diagnostic value and offers novel insights and strategies for the clinical diagnosis and treatment of Endometriosis.

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

Dietary acid load, alternative healthy eating index score, and bacterial vaginosis: is there any association? A case-control study

Background:

Changing the dietary pattern may be an alternative treatment for bacterial vaginosis, the prevalent vaginal infection in women.

Methods:

One hundred and forty-three bacterial vaginosis-affected women diagnosed by Amsel criteria and 151 healthy controls aged 18 to 45 entered the current case-control research. To calculate the alternative healthy eating index and dietary acid load score, food consumption was recorded with an accurate and precise food frequency questionnaire. The dietary acid load was measured by potential renal acid load (PRAL) and net endogenous acid production (NEAP) indices. Using logistic regression models, the association between the alternative healthy eating index and dietary acid load score with bacterial vaginosis was investigated.

Results:

The last tertile of the alternative healthy eating index had a 75% decreased odds of experiencing bacterial vaginosis in the adjusted model (adjusted odds ratio (aOR) = 0.25, 95% confidence interval (CI) = 0.12–0.53, P for trend = 0.001). Besides, vegetables (aOR = 0.34, 95% CI = 0.17–0.69, P for trend = 0.003), nuts and legumes (aOR = 0.44, 95% CI = 0.23–0.87, P for trend = 0.028), and meats (aOR = 0.31, 95% CI = 0.16–0.60, P for trend = 0.001) intake was linked to a decreased bacterial vaginosis odds. However, sugar-sweetened beverages and fruit juice (aOR = 3.47, 95% CI = 1.68–7.17, P for trend < 0.001), trans fatty acids (aOR = 2.29, 95% CI = 1.18–4.43, P for trend = 0.005), and sodium (aOR = 3.44, 95% CI = 1.67–7.06, P for trend = 0.002) intake were directly associated with bacterial vaginosis odds. There was no evidence of a link between dietary acid load and bacterial vaginosis.

Conclusion:

According to the present study’s findings, there is no correlation between dietary acid load and the likelihood of developing bacterial vaginosis. However, following a plant-based dietary pattern based on the healthy eating index may lead to a lower odds of bacterial vaginosis.

Clinical Value of the PD-1/PD-L1/PD-L2 Pathway in Patients Suffering from Endometriosis

The interaction between dendritic cells (DCs) and T cells mediated by the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1)/programmed cell death ligand 2 (PD-L2) pathway is the most important point in regulating immunological tolerance and autoimmunity. Disturbances in the quantity, maturity, and activity of DCs may be involved in the implantation and growth of endometrial tissue outside the uterus in endometriosis (EMS). However, little is known about the role of the immune checkpoint pathways in EMS. In our study, we examined the expression of PD-L1/PD-L2 on myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in the peripheral blood (PB) and peritoneal fluid (PF) of both EMS patients (n = 72) and healthy subjects (n = 20) via flow cytometry. The concentration of soluble PD-L1 and PD-L2 in the plasma and PF of EMS patients and the control group were determined using ELISA. We demonstrated an elevated percentage of mDCs, mDCs and pDCs with the PD-L1or PD-L2 expression, and a higher concentration of the soluble forms of PD-L1 and PD-L2 in the PF than in the plasma of EMS patients. We conclude that the peritoneal cavity environment and the PD-1/PD-L1/PD-L2 axis may play an important role in the modulation of immune response and the development and/or progression of EMS.

Epigenetic regulation and T-cell responses in endometriosis – something other than autoimmunity

Endometriosis is defined as the presence of endometrial-like glands and stroma located outside the uterine cavity. This common, estrogen dependent, inflammatory condition affects up to 15% of reproductive-aged women and is a well-recognized cause of chronic pelvic pain and infertility. Despite the still unknown etiology of endometriosis, much evidence suggests the participation of epigenetic mechanisms in the disease etiopathogenesis. The main rationale is based on the fact that heritable phenotype changes that do not involve alterations in the DNA sequence are common triggers for hormonal, immunological, and inflammatory disorders, which play a key role in the formation of endometriotic foci. Epigenetic mechanisms regulating T-cell responses, including DNA methylation and posttranslational histone modifications, deserve attention because tissue-resident T lymphocytes work in concert with organ structural cells to generate appropriate immune responses and are functionally shaped by organ-specific environmental conditions. Thus, a failure to precisely regulate immune cell transcription may result in compromised immunological integrity of the organ with an increased risk of inflammatory disorders. The coexistence of endometriosis and autoimmunity is a well-known occurrence. Recent research results indicate regulatory T-cell (Treg) alterations in endometriosis, and an increased number of highly active Tregs and macrophages have been found in peritoneal fluid from women with endometriosis. Elimination of the regulatory function of T cells and an imbalance between T helper cells of the Th1 and Th2 types have been reported in the endometria of women with endometriosis-associated infertility. This review aims to present the state of the art in recognition epigenetic reprogramming of T cells as the key factor in the pathophysiology of endometriosis in the context of T-cell-related autoimmunity. The new potential therapeutic approaches based on epigenetic modulation and/or adoptive transfer of T cells will also be outlined.

The Promises of Natural Killer Cell Therapy in Endometriosis

Endometriosis is a gynaecological disease defined by the growth of endometrium-like tissue outside the uterus. The disease is present in approximately 5–10% of women of reproductive age and causes pelvic pain and infertility. The pathophysiology is not completely understood, but retrograde menstruation and deficiency in natural killer (NK) cells that clear endometriotic cells in the peritoneal cavity play an important role. Nowadays, hormonal therapy and surgery to remove endometriosis lesions are used as treatment. However, these therapies do not work for all patients, and hormonal therapy prevents patients from getting pregnant. Therefore, new treatment strategies should be developed. Since the cytotoxicity of NK cells is decreased in endometriosis, we performed a literature search into the possibility of NK cell therapy. Available treatment options include the inhibition of receptor–ligand interaction for KIR2DL1, NKG2A, LILRB1/2, and PD-1/PD-L1; inhibition of TGF-β; stimulation of NK cells with IL-2; and mycobacterial treatment with BCG. In preclinical work, these therapies show promising results but unfortunately have side effects, which have not specifically been studied in endometriosis patients. Before NK cell treatment can be used in the clinic, more research is needed.

Prevalence of Autoimmune Disease in Patients with Eosinophilic Esophagitis: A Cross-sectional Study of Three Hospitals in Japan

Objective Recent studies have found higher rates of autoimmune diseases, such as celiac disease, Crohn's disease, and ulcerative colitis, in patients with eosinophilic esophagitis (EoE) than in the general population. This study investigated the concomitant rate of autoimmune disease among Japanese patients with EoE and evaluated the clinicopathological characteristics of EoE patients with autoimmune disease. Methods The medical records of patients diagnosed with EoE between April 1, 2016, and June 30, 2020, were reviewed. We analyzed the concomitant rate of autoimmune diseases in patients with EoE and compared the clinical and histological differences between patients with and without autoimmune disease. Results Sixty-four patients with EoE were enrolled. Of them, 1 had ulcerative colitis (1.6%), 1 had autoimmune polyendocrine syndrome type 2 (1.6%), and 6 had endometriosis (28.5% of women, 44.4% of reproductive-aged women). No significant differences in the clinical course or histological findings were found between EoE patients with and without autoimmune diseases. No complications, including stenosis, were seen in EoE with autoimmune disease, and most patients with EoE and autoimmune diseases were responsive to proton pump inhibitors (PPIs). Conclusion In this study, 8 out of 64 patients with EoE had an autoimmune-related disease, including ulcerative colitis (n=1, 1.6%), autoimmune polyendocrine syndrome type 2 (n=1, 1.6%), or endometriosis (n=6, 44.4% of women of reproductive age), which is higher than that previously reported in the general population. Further investigations are required to clarify the relationship between EoE and autoimmune diseases.

Circulating and Endometrial Regulatory T Cell and Related Populations in Endometriosis and Infertility: Endometriosis Is Associated with Blunting of Endometrial Cyclical Effects and Reduced Proportions in Moderate-Severe Disease

Evidence to date supports regulatory T cell (Treg) alterations in endometriosis; however, the relationship remains unclear, and Tregs have not previously been investigated with respect to infertility in endometriosis. This prospective cross-sectional cohort study details circulating and endometrial tissue-specific disturbances in Tregs and broader gated populations in women of reproductive age with and without endometriosis (n = 57 and 29, respectively) using flow cytometry and immunohistochemistry. Participants were characterised by menstrual cycle phase, r-ASRM endometriosis disease stage and fertility status.In the endometrium of women with endometriosis, endometrial Tregs and CD4+ lymphocyte proportions did not change between the proliferative and secretory phases, while in women without the disease, they significantly decreased (p = 0.045 and p = 0.039, respectively). In women with endometriosis, endometrial Tregs were lower than in women without endometriosis overall (p = 0.050 as a proportion of all CD45+ immune cells). We have shown for the first time that proportions of CD4+ lymphocytes (p = 0.021), overall lymphocytes (p = 0.034) and non-granulocytes (p = 0.027) were significantly decreased in the endometrium of women with moderate-severe (r-ASRM stages III and IV) compared to minimal-mild (r-ASRM stages I and II) endometriosis. During the secretory phase, circulating Treg proportions were significantly increased in infertile compared to fertile women (p = 0.049). This study confirms differences in endometrial Tregs in women with endometriosis, with blunting of normal menstrual cyclical variations, reduced proportions during the proliferative phase and disease stage-specific relationships.

Association Between Vitamin D Receptor (VDR) and Vitamin D Binding Protein (VDBP) Genes Polymorphisms to Endometriosis Susceptibility in Iranian Women

Endometriosis is a chronic inflammatory disease that has been reported to be associated with immune system dysfunction. On the other hand, the effect of Vitamin D as an immune modulator and its relation with several autoimmune and inflammatory diseases has been previously investigated. Moreover, several studies have reported the polymorphisms of VDR and VDBP genes can change the functions of these molecules. Therefore, these polymorphisms may be influential on endometriosis pathogenesis. In this study, we aimed at evaluating the association between VDR gene (FokI (F/f), BsmI (B/b), ApaI (A/a), TaqI (T/t)), and VDBP gene (GC*1S, GC*1F, and GC*2) polymorphisms with endometriosis in Iranian women population. This case-control study was performed on 120 women with endometriosis and 110 healthy women. ARMS-PCR and PCR-RFLP methods were used to inspect polymorphisms in VDR and VDBP genes, respectively. Based on the results, there was no statistically significant difference between the cases with endometriosis and control subjects in terms of genotypes and allele frequencies of VDR and VDBP gene polymorphisms. These data suggest that VDR and VDBP gene polymorphisms may have no role in endometriosis susceptibility in Iranian women.