CLTA-4 Expression is Associated with the Maintenance of Chronic Inflammation in Endometriosis and Infertility

Immune Checkpoints in Endometriosis-A New Insight in the Pathogenesis

Endometriosis (EMS) is an oestrogen-dependent, chronic disease affecting women of a reproductive age. One of the important factors involved in the development of this disease is the complex disorders associated with the functioning of the immune system. Recent evidence has shown that EMS development is associated with changes in systemic and local immunity, including functional disturbances of effector and antigen-presenting cells. One of the reasons for immune imbalance can be the improper expression of immune checkpoints (ICPs). ICPs and their ligands are responsible for maintaining self-tolerance and the modulation of the initiation, duration, and magnitude of the immune response of effector cells in normal tissues to avoid tissue damage. Considering the complex nature of co-stimulatory or co-inhibitory ICPs and the signalling between effector cells and APCs, we hypothesise that changes in cells' activity caused by ICPs may lead to serious immune system disturbances in patients with endometriosis. Moreover, both upregulation and downregulation in the expression of ICPs may be implicated in this process, including the reduced activity of effector cells against endometrial implants and disturbances in the antigen-presenting process. In this narrative review, we discuss, for the first time, key findings from the emerging literature, describing the associations between ICPs and their possible implication in the pathogenesis of endometriosis.

Role of Molecular Biomarkers in Endometriosis-Related Infertility: A Narrative Review of the Literature

Endometriosis is a chronic benign inflammatory disease that affects women of reproductive age. The clinical presentations of endometriosis include dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility. There is a well-established association between endometriosis and infertility. Therefore, there is a need for an early diagnosis of endometriosis-related infertility. In this study, we aim to identify the role of biomarkers as predictive factors of the presence of the disease and its severity and their correlation with the pregnancy outcome. We performed an electronic database search of all published studies in PubMed and EMBASE from January 2018 to May 2023. Numerous innovative biomarkers identified in cases of endometriosis and infertility have been studied over the past years, including micro-RNAs, BCL6 endometrial expression, cytotoxic T-lymphocyte antigen 4, human leukocyte antigen G, programmed cell death protein 1, programmed cell death ligand 1 immune checkpoint molecules, plasma fibronectin-fibrin complexes, homeobox A10 gene, systemic inflammatory response markers, uterine natural killer cells, and the eutopic endometrium proteome. Considerable research has been done to identify diagnostic biomarkers for the early detection and prevention of endometriosis-associated infertility. However, none of these biomarkers displayed enough diagnostic accuracy to be used in daily clinical practice. Future research is valuable to establish them as reliable diagnostic tools.

The regulation of methylation on the Z chromosome and the identification of multiple novel Male Hyper-Methylated regions in the chicken

DNA methylation is a key regulator of eukaryote genomes, and is of particular relevance in the regulation of gene expression on the sex chromosomes, with a key role in dosage compensation in mammalian XY systems. In the case of birds, dosage compensation is largely absent, with it being restricted to two small Male Hyper-Methylated (MHM) regions on the Z chromosome. To investigate how variation in DNA methylation is regulated on the Z chromosome we utilised a wild x domestic advanced intercross in the chicken, with both hypothalamic methylomes and transcriptomes assayed in 124 individuals. The relatively large numbers of individuals allowed us to identify additional genomic MHM regions on the Z chromosome that were significantly differentially methylated between the sexes. These regions appear to down-regulate local gene expression in males, but not remove it entirely (unlike the lncRNAs identified in the initial MHM regions). These MHM regions were further tested and the most balanced genes appear to show decreased expression in males, whilst methylation appeared to be far more correlated with gene expression in the less balanced, as compared to the most balanced genes. In addition, quantitative trait loci (QTL) that regulate variation in methylation on the Z chromosome, and those loci that regulate methylation on the autosomes that derive from the Z chromosome were mapped. Trans-effect hotspots were also identified that were based on the autosomes but affected the Z, and also one that was based on the Z chromosome but that affected both autosomal and sex chromosome DNA methylation regulation. We show that both cis and trans loci that originate from the Z chromosome never exhibit an interaction with sex, whereas trans loci originating from the autosomes but affecting the Z chromosome always display such an interaction. Our results highlight how additional MHM regions are actually present on the Z chromosome, and they appear to have smaller-scale effects on gene expression in males. Quantitative variation in methylation is also regulated both from the autosomes to the Z chromosome, and from the Z chromosome to the autosomes.

Identification of central genes for endometriosis through integration of single-cell RNA sequencing and bulk RNA sequencing analysis

This study aimed to identify the key genes involved in the development of endometriosis and construct an accurate predictive model to provide new directions for the diagnosis and treatment of endometriosis. Using bioinformatics analysis, we employed the single-cell cell communication method to identify the key cell subtypes. By combining chip data and integrating differential analysis, WGCNA analysis, and the least absolute shrinkage and selection operator (LASSO) model, key genes were identified for immune infiltration and functional enrichment analyses. Cell communication analysis identified tissue stem cells as the key subtype. Differential analysis revealed 1879 differentially expressed genes, whereas WGCNA identified 357 module genes. The LASSO model further selects 4 key genes: Adipocyte Enhancer Binding Protein 1(AEBP1), MBNL1, GREM1, and DES. All 4 key genes showed significant correlations with immune cell content. Moreover, these genes were significantly expressed in single cells. The predictive model demonstrated good diagnostic performance. Through scRNA-seq, WGCNA, and LASSO methodologies, DES, GREM1, MBNL1, and AEBP1 emerged as crucial core genes linked to tissue stem cell markers in endometriosis. These genes have promising applications as diagnostic markers and therapeutic targets for endometriosis.

Protein Expression Profiles in Exosomes of Bovine Mammary Epithelial Cell Line MAC-T Infected with Staphylococcus aureus

Mastitis is a common and widespread infectious disease in dairy farms around the world, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis in dairy cows. S. aureus can activate inflammatory signaling pathways in bovine mammary epithelial cells. Exosomes produced by cells can directly transfer pathogen-related molecules from cell to cell, thus affecting the process of infection. Protein is the material basis of the immune defense function in the body; therefore, a comprehensive comparison of proteins in exosomes derived from S. aureus-infected (SA group) and normal (control group [C group]) bovine mammary epithelial MAC-T cells was performed using shotgun proteomics by a DIA approach. A total of 7,070 proteins were identified and quantified. Compared with the C group, there were 802 differentially expressed proteins (DEPs) identified in the SA group (absolute log2 fold change [|log2FC|] of ≥0.58; false discovery rate [FDR] of <0.05), among which 325 proteins were upregulated and 477 were downregulated. The upregulated proteins, including complement 3 (C3), integrin alpha-6 (ITGA6), apolipoprotein A1 (APOA1), annexin A2 (ANXA2), tripeptidyl peptidase II (TPP2), keratin 8 (KRT8), and recombinant desmoyokin (AHNAK), are involved mostly in host defense against pathogens, inflammation, and cell structure maintenance. KEGG enrichment analysis indicated that DEPs in S. aureus infection were involved in the complement and coagulation cascade, phagosome, extracellular matrix (ECM)-receptor interaction, and focal adhesion pathways. The results of this study provide novel information about proteins in the exosomes of MAC-T cells infected with S. aureus and could contribute to an understanding of the infectious mechanism of bovine mastitis. IMPORTANCE Mastitis is a widespread infectious disease in dairy farms, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis. Exosomes contain proteins, lipids, and nucleic acids, which are involved in many physiological and pathological functions. The expression of proteins in exosomes derived from bovine mammary epithelial cells infected by S. aureus is still barely understood. These results provide novel information about MAC-T-derived exosomal proteins, reveal insights into their functions, and lay a foundation for further studying the biological function of exosomes during the inflammatory response.

CTLA-4 Expression Is a Promising Biomarker of Idiopathic Pulmonary Arterial Hypertension and Allows Differentiation of the Type of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is an increasingly frequently diagnosed disease, the molecular mechanisms of which have not been thoroughly investigated. The aim of our study was to investigate subpopulations of lymphocytes to better understand their role in the molecular pathomechanisms of various types of PAH and to find a suitable biomarker that could be useful in the differential diagnosis of PAH. Using flow cytometry, we measured the frequencies of lymphocyte subpopulations CD4+CTLA-4+, CD8+ CTLA-4+ and CD19+ CTLA-4+ in patients with different types of PAH, namely pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH), pulmonary arterial hypertension associated with connective tissue disorders (CTD-PAH), chronic thromboembolic pulmonary hypertension (CTEPH) and idiopathic pulmonary arterial hypertension (iPAH), and in an age- and sex-matched control group in relation to selected clinical parameters. Patients in the iPAH group had the significantly highest percentage of CD4+CTLA-4+ T lymphocytes among all PAH groups, as compared to those in the control group (p < 0.001), patients with CTEPH (p < 0.001), CTD-PAH (p < 0.001) and CHD-PAH (p < 0.01). In iPAH patients, the percentages of CD4+CTLA-4+ T cells correlated strongly positively with the severity of heart failure New York Heart Association (NYHA) Functional Classification (r = 0.7077, p < 0.001). Moreover, the percentage of B CD19+CTLA-4+ cells strongly positively correlated with the concentration of NT-proBNP (r = 0.8498, p < 0.001). We have shown that statistically significantly higher percentages of CD4+CTLA-4+ (p ≤ 0.01) and CD8+ CTLA-4+ (p ≤ 0.001) T cells, measured at the time of iPAH diagnosis, were found in patients who died within 5 years of the diagnosis, which allows us to consider both of the above lymphocyte subpopulations as a negative prognostic/predictive factor in iPAH. CTLA-4 may be a promising biomarker of noninvasive detection of iPAH, but its role in planning the treatment strategy of PAH remains unclear. Further studies on T and B lymphocyte subsets are needed in different types of PAH to ascertain the relationships that exist between them and the disease.

CTLA4-Linked Autoimmunity in the Pathogenesis of Endometriosis and Related Infertility: A Systematic Review

Several studies, although with conflicting results, have sought to determine the concentration of soluble CTLA4 antigens in peripheral blood plasma and peritoneal fluid in patients with endometriosis-related infertility. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) through a search of the following databases: MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database and Web of Science, and Clinical Trials research register. We included observational or prospective human and animal studies with any features related to endometriosis and/or infertility studies involving CTLA4-related pathogenesis published in English. The results of studies in which the size and characteristics of the observed groups were not stated were excluded. From the initial pool of 73 publications identified and screened, we finally included 5 articles to summarize the most recent knowledge about CTLA4-linked autoimmunity in the pathogenesis of endometriosis and related infertility. Evidence from clinical studies shows that CTLA4-based autoimmunity is involved in the maintenance of chronic inflammation in the peritoneal environment, with pre-clinical evidence of anti-CTLA antibodies as a potential novel target therapy for endometriosis. However, CTLA4 gene analyses do not support findings of CTLA4-linked autoimmunity as a primary determinant of the pathogenesis of endometriosis. These findings underlie the role of complex interactions within the family of immune checkpoint molecules involved. Further studies are needed to investigate the clinical relevance of anti-CTLA target therapy, taking into account the potential adverse events and repercussions of novel immunologic therapy modalities. However, with the general scarcity of studies investigating this topic, the clinical importance of CTLA4 autoimmunity still remains unclear.

Mesenchymal Stromal Cells Isolated from Ectopic but Not Eutopic Endometrium Display Pronounced Immunomodulatory Activity In Vitro

A comparative analysis of the cell surface markers and immunological properties of cell cultures originating from normal endometrium and endometrioid heterotopias of women with extragenital endometriosis was carried out. Both types of cell cultures expressed surface molecules typical of mesenchymal stromal cells and did not express hematopoietic and epithelial markers. Despite similar phenotype, the mesenchymal stromal cells derived from the two sources had different immunomodulation capacities: the cells of endometrioid heterotopias but not eutopic endometrium could suppress dendritic cell differentiation from monocytes as well as lymphocyte proliferation in allogeneic co-cultures. A comparative multiplex analysis of the secretomes revealed a significant increase in the secretion of pro-inflammatory mediators, including IL6, IFN-γ, and several chemokines associated with inflammation by the stromal cells of ectopic lesions. The results demonstrate that the stromal cells of endometrioid heterotopias display enhanced pro-inflammatory and immunosuppressive activities, which most likely impact the pathogenesis and progression of the disease.

Differential Response of MDA-MB-231 and MCF-7 Breast Cancer Cells to In Vitro Inhibition with CTLA-4 and PD-1 through Cancer-Immune Cells Modified Interactions

Drugs targeting immune checkpoint molecules have been found effective in melanoma, lung cancer, and other malignancies treatment. Recent studies on breast cancer demonstrated the significance of inhibitory anti-CTLA-4 and anti-PD-1 in the regulation of disease progression. However, seemingly the same types of breast cancer do not always respond unambiguously to immunotherapy. Thus, here we set out to analyze the in vitro effects of inhibiting CTLA-4 and PD-1 on interactions between co-cultured lymphocytes and two selected breast adenocarcinoma cell lines. Breast cancer cells were co-cultured with lymphocytes to evaluate the effects of CTLA-4 and PD-1 inhibition. Proliferation, cell cycle, and viability assessment were measured in cancer cells. IFN-gamma, IL-10, perforin, granzyme B production, and CTLA-4 and PD-1 expression were analyzed in lymphocytes. We found that administration of anti-CTLA-4 improved the anti-cancer activity of T cells with reduced proliferation and viability of MDA-MB-231. Lack of response was observed in the context of MCF-7. In addition, differential expression of checkpoint proteins was found between studied cancer cells lines. Inhibition of molecules was followed by IL-10 and IFN-gamma decrease in lymphocytes co-cultured with MDA-MB-231, not demonstrated in reference to MCF-7. Furthermore, CTLA-4 blockage was associated with reduction of CTLA-4+ and PD-1+ lymphocytes in MDA-MB-231, with a significant increase in MCF-7, reduced by anti-PD-1. Altogether, our study revealed that anti-CTLA-4 and anti-PD-1 treatment can improve lymphocytes effects on breast cancer cells. Favorable effects seemed to be related to breast cancer cells features as differential responses were reported. Novel blocking antibodies strategies should be tested for more effective cancer inhibition.