Tubal origin of ovarian endometriosis

Immune micro-environment analysis and drug screening for ovarian endometriosis

BACKGROUND

Patients of ovary endometriosis have an abnormal immune micro-environment, leading to endometrial tissue that from retrograde menstruation evade immune surveillance and subsequently develop into ectopic lesions.

OBJECTIVE

This study aims to elucidate the crucial immune cells and molecular pathways that are associated with an aberrant immune micro-environment of endometriosis.

METHOD

In this study, we identified differentially expressed genes between ovarian ectopic endometrial tissue (OVE) and eutopic endometrial tissue from patients with endometriosis (PE) and non-endometriosis patients (CON) by analyzing the mRNA sequencing data. Additionally, we used WGCNA(Weighted Gene Co-expression Network Analysis) to screen for key genes related to immune cell infiltration and compared the sub-types of infiltrating immune cells using CIBERSORT(cell-type identification by estimating relative subsets of RNA transcript). Subsequently, we conducted a single-cell analysis on the identified key genes. Furthermore, we analyzed potential drugs suitable for ovarian endometriosis treatment using pRRophertic.

RESULTS

Seven key genes associated with immune cell infiltration were screened out. The expression of these genes in OVE was significantly lower than that in PE and CON. These key genes were mainly enriched in the NK cell-mediated cytotoxicity pathway, especially for CD16 + CD56dim NK. Moreover, NK cells infiltration in ovarian endometriosis was significantly reduced compared with PE and CON, while M2 macrophage shown the opposite. Results of the single-cell analysis showed that the expression of the seven key genes in NK cells and monocyte-macrophages in OVE was significantly lower than that in PE or CON. Additionally, we identified potential drugs suitable for ovarian endometriosis treatment.

CONCLUSION

The decreased infiltration of NK cells and increased infiltration of M2 macrophages contribute to the evasion of immune surveillance against endometrial tissue, promoting the progression of OVE. Therefore, potential strategies for the treatment of OVE include increasing NK cell activation and decreasing M2 macrophage polarization.

DNA methylation profiles of ovarian cysts resemble ovarian tissues but not endometrial tissues

INTRODUCTION

Endometriosis is a heritable, complex chronic inflammatory disease, for which much of the causal pathogenic mechanism remain unknown.Despite the high prevalence of ovarian chocolate cyst, its origin is still under debate.

METHODS

Prevailing retrograde menstruation model predicts that ectopic endometrial cells migrate and develop into ovarian chocolate cyst. However, other models were also proposed. Genome-wide association studies (GWASs) have proved successful in identifying common genetic variants of moderate effects for various complex diseases.

RESULTS

A growing body of evidence shows that the remodeling of retrograde endometrial tissues to the ectopic endometriotic lesions involves multiple epigenetic alterations, such as DNA methylation, histone modification, and microRNA expression.Because DNA methylation states exhibit a tissue specific pattern, we profiled the DNA methylation for ovarian cysts and paired eutopic endometrial and ovarian tissues from four patients. Surprisingly, DNA methylation profiles showed the ovarian cysts were closely grouped with normal ovarian but not endometrial tissues.

CONCLUSIONS

These results suggested alterative origin of ovarian cysts or strong epigenetic reprogramming of infiltrating endometrial cells after seeding the ovarian tissue. The data provide contributing to the pathogenesis and pathophysiology of endometriosis.

Fallopian tubal histogenesis of ovarian endometriosis-A study of folate receptor-alpha expression

Background

Ovary is a common organ site involved by endometriosis. We previously found that fallopian tube may contribute to the histogenesis of ovarian endometriosis. The finding was novel and requires further studies. We addressed this issue by examining a differentially expressed gene folate receptor alpha (FOLR1) and its protein (FRA) in this study.

Results

A total of 144 tissue samples were studied. These included 32-paired tubal-endometrial-ovarian endometriosis samples (n = 96), 18 samples of ovarian endometriosis without corresponding fallopian tube or endometrium, and 30 ovarian tissue samples with ovarian surface epithelia but without endometriosis. Multiple comparisons among groups of ovarian endometriosis, normal fallopian tube and benign endometrium were performed. FOLR1 was highly expressed in the epithelia of fallopian tube and ovarian endometriosis, with paired endometrial samples showing a significantly lower level of expression. Similar differential studies for FRA protein were performed through Western blot and immunohistochemistry (IHC). The expression of folate receptor alpha at both mRNA and protein levels in the tissues (fallopian tube or ovarian endometriosis vs. the endometrium) were significantly different (p < 0.001). All ovarian surface mesothelial epithelia showed negative expression of FRA by IHC.

Conclusion

The results further support that the fallopian tube may contribute to the development of ovarian endometriosis. Understanding the tubal contribution to ovarian endometriosis should ultimately contribute to ongoing investigative efforts aimed at identifying alternative ways to prevent and treat endometriosis. High level of FRA expression in the fallopian tube and endometriosis might be considered as potential tissue sites for targeted therapy.

Diagnosis and treatment of tubal endometriosis in women undergoing laparoscopy: A case series from a single hospital

BACKGROUND

Tubal endometriosis (TEM) is a category of pelvic endometriosis (EM) that is characterized by ectopic endometrial glands and/or stroma within any part of the fallopian tube. The fallopian tubes may be a partial source of ovarian endometriosis (OEM). TEM is difficult to diagnose during surgery and is usually detected by pathology after surgery.

AIM

To provide a clinical basis for the diagnosis and treatment of TEM.

METHODS

In this study, the data of 30 patients who underwent laparoscopic salpingectomy due to various gynecological diseases and had pathological confirmation of TEM at our hospital were retrospectively analyzed, and the clinical basis for the diagnosis and treatment of TEM was evaluated.

RESULTS

Among 1982 surgical patients, 30 met the study criteria. Among those, 6 patients had a history of infertility, 12 patients had a history of artificial abortion, 13 patients had a history of cesarean section, 1 patient had a history of tubal ligation, 4 patients had an intrauterine device, and 22 patients had hydrosalpinx. Sixteen patients (53.33%) conceived naturally and gave birth to healthy babies. Pathology showed that only 2 patients had TEM without any other gynecological diseases, while the others all had simultaneous diseases, including 26 patients with EM at other pelvic sites.

CONCLUSION

The final diagnosis of TEM depends on pathological examination since there are no specific clinical characteristics. The rate of TEM combined with EM (especially OEM) was higher than that of other gynecological diseases, which indicates that TEM is related to OEM.

Does the "Devil" originate from the fallopian tubes?

Epithelial ovarian cancer (OC) is a heterogeneous disease and continues to be mostly diagnosed in advanced stages. The high lethality, the high rate of platinum-resistance, and the poor survival outcomes are the principal factors for categorizing OC among the most aggressive gynecological cancers. Only recently, a substantial progress has been made in our latest understanding of the origins of OC, particularly of high-grade serous histology. For a long time, the accumulation of genetic alterations in epithelial single layer cells of ovarian cysts caused by cyclic ovulations was considered as the most important driver and the long-standing dogma of ovarian tumorigenesis. Besides, the unique biological features and high histological heterogeneity of OC did not support this hypothesis. Indeed, various extra-ovarian cells of origin and multiple sites to each histotype were proposed, supported by cogent evidence from clinical cohorts and animal studies. In light of this enigma, this review was conducted to discuss the recent evidence supporting the revised origins of ovarian carcinoma histotypes with a particular focus on high-grade serous OC which may impact diagnostic and preventive approaches.

Circular RNA PIP5K1A (circPIP5K1A) accelerates endometriosis progression by regulating the miR-153-3p/Thymosin Beta-4 X-Linked (TMSB4X) pathway

As a common gynecologic disease, endometriosis (EM) poses a threat to the reproductive health of about 10% women globally. Recent studies have revealed that circular RNAs (circRNAs) are deeply implicated in EM pathogenesis. However, the functions of circPIP5K1A in EM have not been studied yet. Our study intended to uncover the molecular mechanism of circPIP5K1A in EM. In this work, gene and protein expressions were determined by RT-qPCR or Western blotting. CCK-8, wound healing, transwell, and flow cytometry assays were conducted to analyze cell viability, migration, invasion, cell cycle, and apoptosis. Additionally, bioinformatics analysis, dual-luciferase reporter assay, as well as RIP assay were performed to investigate the combination between miR-153-3p and circPIP5K1A or TMSB4X. Herein, we found remarkable high circPIP5K1A expression in EM tissues and cells. Silencing of circPIP5K1A suppressed proliferation, restrained cell cycle, increased cell apoptosis, and decreased migration and invasion in EM cells. In addition, miR-153-3p inhibition could abrogate the impacts of circPIP5K1A knockdown on EM progression in vitro. Also, we found that circPIP5K1A regulated TMSB4X level via interaction with miR-153-3p in EM cells. Besides, circPIP5K1A promoted EM progression via TMSB4X. Moreover, TMSB4X could activate the TGF-β signaling in hEM15A cells. To sum up, our study elucidated that circPIP5K1A accelerated EM progression in vitro by activating the TGF-β signaling pathway via the miR-153-3p/TMSB4X axis, providing a potential clinical target for EM treatment.

Endometriosis and the Fallopian Tubes: Theories of Origin and Clinical Implications

Endometriosis is a common, oestrogen driven chronic condition, where endometrium-like epithelial and stromal cells exist in ectopic sites. At present, no curative treatments are available and the existing evidence for disease progression is conflicting. The pathogenesis is still unknown and evidently complex, as mechanisms of initiation may depend on the anatomical distribution of endometriotic lesions. However, amongst the numerous theories and plethora of mechanisms, contributions of the fallopian tubes (FT) to endometriosis are rarely discussed. The FT are implicated in all endometriosis associated symptomatology and clinical consequences; they may contribute to the origin of endometriotic tissue, determine the sites for ectopic lesion establishment and act as conduits for the spread of proinflammatory media. Here, we examine the available evidence for the contribution of the human FT to the origin, pathogenesis and symptoms/clinical consequences of endometriosis. We also examine the broader topic linking endometriosis and the FT epithelium to the genesis of ovarian epithelial cancers. Further studies elucidating the distinct functional and phenotypical characteristics of FT mucosa may allow the development of novel treatment strategies for endometriosis that are potentially curative.

Genetic, Epigenetic, and Steroidogenic Modulation Mechanisms in Endometriosis

Endometriosis is a chronic gynecological disease, affecting up to 10% of reproductive-age women. The exact cause of the disease is unknown; however, it is a heritable condition affected by multiple genetic, epigenetic, and environmental factors. Previous studies reported variations in the epigenetic patterns of numerous genes known to be involved in the aberrant modulation of cell cycle steroidogenesis, abnormal hormonal, immune and inflammatory status in endometriosis, apoptosis, adhesion, angiogenesis, proliferation, immune and inflammatory processes, response to hypoxia, steroidogenic pathway and hormone signaling are involved in the pathogenesis of endometriosis. Accumulating evidence suggest that various epigenetic aberrations may contribute to the pathogenesis of endometriosis. Among them, DNA methyltransferases, histone deacetylators, and non-coding microRNAs demonstrate differential expression within endometriotic lesions and in the endometrium of patients with endometriosis. It has been indicated that the identification of epigenetic differences within the DNA or histone proteins may contribute to the discovery of a useful prognostic biomarker, which could aid in the future earlier detection, timely diagnosis, and initiation of a new approach to the treatment of endometriosis, as well as inform us about the effectiveness of treatment and the stage of the disease. As the etiology of endometriosis is highly complex and still far from being fully elucidated, the presented review focuses on different approaches to identify the genetic and epigenetic links of endometriosis and its pathogenesis.

Uterine endosalpingiosis: Case report and review of the literature

OBJECTIVE

Endosalpingiosis rarely occurs in the uterus. We report a case and review literature to explore its current clinical diagnosis and treatment.

CASE REPORT

A 31-year-old woman was admitted to the hospital for suspected uterine leiomyoma with cystic degeneration based on ultrasound and magnetic resonance imaging and surgical treatment. Laparoscopy revealed a large cystic mass protruding from the posterior uterine wall. The mass was resected, and a histologic examination showed that the cyst wall was lined with benign fallopian tube-type ciliated epithelium surrounded by normal myometrium, consistent with the diagnosis of endosalpingiosis of the uterus (also known as a Müllerian cyst). Currently, there are 18 cases (including ours) in the literature. Of these, two had a uterine malignancy, one endometrioid endometrial carcinoma, and another cervical adenocarcinoma. The age at diagnosis varied from 31 to 73, with a mean of 47 ± 8. The typical clinical manifestations were a palpable low abdominal mass, abnormal menstrual bleeding, and pelvic pain. Overall, 75% (12 of 16) of patients underwent a total hysterectomy, while 62.5% (10 in 16) had a concomitant bilateral salpingo-oophorectomy for nonmalignancy. No recurrence was reported.

CONCLUSION

We describe the youngest patient with tumor-like uterine endosalpingiosis. The preoperative diagnosis is challenging because of its rarity. Most patients had a hysterectomy with castration, which may have resulted in overtreatment. Awareness of this lesion is necessary for the differential diagnosis of uterine and adnexal tumors. Review of relevant literature has shown a relationship between endosalpingiosis progression and cancer development, indicating an uncertain and complicated pathology.

The risk of endometriosis after exposure to endocrine-disrupting chemicals: a meta-analysis of 30 epidemiology studies

Endocrine-disrupting chemicals (EDCs) are suspected to be associated with endometriosis (EMs). This study aimed to synthesize published data and evaluate the relationship between four classic EDCs exposure and the risk of EMs. A systematic literature search for original peer reviewed papers was performed in the databases PubMed, EMBASE, and Web of Science based on inclusion criteria up to January 2018. Subsequently, a total of 20 papers conducting 30 studies fulfilled the eligibility criteria and were included in this meta-analysis (four studies for bisphenol A (BPA), 12 studies for polychlorinated biphenyls (PCBs), eight studies for organochlorine pesticides (OCPs), and six studies for phthalate esters (PAEs)). The overall odds ratio (OR) across all exposures and EMs was 1.41 (95% confidence interval (CI): 1.23-1.60). When assessing four specific chemicals, respectively, consistent increases in the risk of EMs were found in PCBs group (OR = 1.58; 95% CI: 1.18-2.12), OCPs group (OR = 1.40; 95% CI: 1.02-1.92) and PAEs group (OR = 1.27; 95% CI: 1.00-1.60), while BPA showed no significant association with EMs. Besides, in the di-(2-ethylhexyl)-phthalate (DEHP) group - the most commonly used PAEs, significant risk was also found (OR = 1.42; 95% CI: 1.19-1.70). The current meta-analysis strengthens the evidence that specific EDCs or their metabolites may promote the occurrence of EMs.

Tubal Origin of "Ovarian" Low-Grade Serous Carcinoma: A Gene Expression Profile Study

Objective

Ovarian low-grade serous carcinomas are thought to evolve in a stepwise fashion from ovarian epithelial inclusions, serous cystadenomas, and serous borderline tumors. Our previous study with clinicopathological approach showed that the majority ovarian epithelial inclusions are derived from the fallopian tubal epithelia rather than from ovarian surface epithelia. This study was designed to gain further insight into the cellular origin of ovarian low-grade serous carcinomas by differential gene expression profiling studies.

Methods

Gene expression profiles were studied in 43 samples including 11 ovarian low-grade serous carcinomas, 7 serous borderline tumors, 6 serous cystadenomas, 6 ovarian epithelial inclusions, 7 fallopian tubal epithelia, and 6 ovarian surface epithelia. Comprehensive analyses with hierarchical clustering, Rank-sum analysis and Pearson correlation tests were performed. Final validation was done on selected genes and corresponding proteins.

Results

The gene expression profiles distinguished ovarian low-grade serous carcinomas from ovarian surface epithelia, but not from fallopian tubal epithelia cells. Hierarchical clustering analysis showed ovarian serous tumors and ovarian epithelial inclusions were clustered closely in a branch, but separated from ovarian surface epithelia. The results were further validated by selected proteins of OVGP1, WT-1, and FOM3, which were highly expressed in the samples of the fallopian tube, ovarian epithelial inclusions, and ovarian serous tumors, but not in ovarian surface epithelia. The reverse was true for the protein expression patterns of ARX and FNC1.

Conclusions

This study provides evidence in a molecular level that ovarian low-grade serous carcinomas likely originate from the fallopian tube rather than from ovarian surface epithelia. Similar gene expression profiles among fallopian tube, ovarian epithelial inclusions, and serous tumors further support that ovarian low-grade serous carcinomas develop in a stepwise fashion. Such findings may have a significant implication for “ovarian” cancer-prevention strategies.

Origin of clear cell carcinoma: nature or nurture?

A rare but serious complication of endometriosis is the development of carcinoma, and clear cell and endometrioid carcinomas of the ovary are the two most common malignancies which arise from endometriosis. They are distinct diseases, characterized by unique morphologies, immunohistochemical profiles, and responses to treatment. However, both arise in endometriosis and can share common mutations. The overlapping mutational profiles of clear cell and endometrioid carcinomas suggest that their varied histologies may be due to a different cell of origin which gives rise to each type of cancer. Cochrane and colleagues address this question in a recent article in this journal. They show that a marker of ovarian clear cell carcinoma, cystathionine gamma lyase, is expressed in ciliated cells. Similarly, they show that markers of secretory cells (estrogen receptor and methylenetetrahydrofolate dehydrogenase 1) are expressed in ovarian endometrioid carcinoma. Taken together, they suggest that endometrioid and clear cell carcinomas arise from cells related to secretory and ciliated cells, respectively. We discuss Cochrane et al's work in the context of other efforts to determine the cell of origin of gynecological malignancies, with an emphasis on recent developments and challenges unique to the area. These limitations complicate our interpretation of tumor differentiation; does it reflect nature imposed by a specific cell of origin or nurture, by either mutation(s) or environment? Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Characterization of the cervical mucus plug in mares

The cervical mucus plug (CMP) is believed to play an integral role in the maintenance of pregnancy in the mare, primarily by inhibiting microbial entry. Unfortunately, very little is known about its composition or origin. To determine the proteomic composition of the CMP, we collected CMPs from mares (n = 4) at 9 months of gestation, and proteins were subsequently analyzed by nano-LC–MS/MS. Results were searched against EquCab2.0, and proteomic pathways were predicted by Ingenuity Pathway Analysis. Histologic sections of the CMP were stained with H&E and PAS. To identify the origin of highly abundant proteins in the CMP, we performed qPCR on endometrial and cervical mucosal mRNA from mares in estrus, diestrus as well as mares at 4 and 10 m gestation on transcripts for lactotransferrin, uterine serpin 14, uteroglobin, uteroferrin, deleted in malignant brain tumors 1 and mucins 4, 5b and 6. Overall, we demonstrated that the CMP is composed of a complex milieu of proteins during late gestation, many of which play an important role in immune function. Proteins traditionally considered to be endometrial proteins were found to be produced by the cervical mucosa suggesting that the primary source of the CMP is the cervical mucosa itself. In summary, composition of the equine CMP is specifically regulated not only during pregnancy but also throughout the estrous cycle. The structural and compositional changes serve to provide both a structural barrier as well as a physiological barrier during pregnancy to prevent infection of the fetus and fetal membranes.

1-Methyl-tryptophan attenuates regulatory T cells differentiation due to the inhibition of estrogen-IDO1-MRC2 axis in endometriosis

Foxp3⁺ regulatory T (T_reg) cells contribute to the local dysfunctional immune environment in endometriosis, an estrogen-dependent gynecological disease, which affects the function of ectopic endometrial tissue clearance by the immune system. The reason for the high percentage of peritoneal T_reg in endometriosis patients is unknown. Here, we show that the proportion of peritoneal T_reg cells increases as endometriosis progresses. To determine the probable mechanism, we established a naive T cell-macrophage-endometrial stromal cell (ESC) co-culture system to mimic the peritoneal cavity microenvironment. After adding 1-methyl-tryptophan (1-MT), a specific inhibitor of indoleamine 2,3-dioxygenase-1 (IDO1), to the co-culture system, we found that the differentiation of T_reg cells, mainly IL-10⁺ T_reg cells, decreased. Therefore, 1-MT-pretreated ESCs-educated T_reg cells performed impaired suppressive function. Moreover, estrogen promoted the differentiation of T_reg cells by elevating IDO1 expression in the ectopic lesion. Subsequently, we examined mannose receptor C, type 2 (MRC2), which is an up-stream molecule of IL-10, by bioinformatics analysis and real-time PCR validation. MRC2 expression in ectopic ESCs was notably lower than that in normal ESCs, which further negatively regulated the expression of IDO1 and Ki-67 in ESCs. Furthermore, MRC2 is required for T_reg differentiation in the ectopic lesion, especially that for CD4^high T_reg. Therefore, MRC2-silenced ESCs-educated T_reg manifested a stronger suppressive function in vitro. Consistently, the percentage of T_reg increased when MRC2-shRNA was administered in the peritoneal cavity of endometriosis-disease mice model. Besides, 1-MT improved the condition of endometriosis, in terms of reducing the number and weight of total ectopic lesions in vivo. These results indicate that the estrogen-IDO1-MRC2 axis participates in the differentiation and function of T_reg and is involved in the development of endometriosis. Thus, blockage of IDO1 in the ectopic lesion, which does not influence physiological functions of estrogen, may be considered a potential therapy for endometriosis.

Pooling-Based Genome-Wide Association Study Identifies Risk Loci in the Pathogenesis of Ovarian Endometrioma in Chinese Han Women

Endometriosis, regarded as a complex disease, is influenced by multiple genetic factors. Recent genome-wide association studies (GWASs) in endometriosis have identified several susceptibility loci in Caucasian and Japanese populations. However, the overlapped susceptible loci were few. This case-control study tried to identify risk loci-related genes for ovarian endometrioma in Chinese Han women from central China using DNA pooling-based GWAS. Genome DNA samples were extracted from 3038 participants in central China. Pooling-based genome-wide scan and individual genotyping were performed using Affymetrix Genome-Wide Human SNP Array 6.0 and IPLEX Gold system, which demonstrated 10 ovarian endometrioma-related novel risk loci. There were 3 of them with P value < 5 × 10^-06, separately locating in intron of insulin-like growth factor 1 receptor, chromosome 7 open reading frame 50, and Meis homeobox 1. In conclusion, the pooling-based GWAS for ovarian endometrioma identified some novel single-nucleotide polymorphisms in Chinese Han women of central China. Further assessment in other samples will be crucial to confirm the susceptibility of these results and explore the mechanisms of the related genes in the pathogenesis of ovarian endometrioma.

Transcriptomic analysis of stage 1 versus advanced adult granulosa cell tumors

Ovarian granulosa cell tumors (GCT) are hormonally-active neoplasms characterized, in the adult-subtype, by a mutation in the FOXL2 gene (C134W). They exhibit an indolent course with an unexplained propensity for late recurrence; ~80% of patients with aggressive, advanced stage tumors die from their disease; aside from surgery, therapeutic options are limited. To identify the molecular basis of advanced stage disease we have used whole transcriptome analysis of FOXL2 C134W mutation positive adult (a)GCT to identify genes that are differentially expressed between early (stage 1) and advanced (stage 3) aGCT. Transcriptome profiles for early (n = 6) and stage 3 (n = 6) aGCT, and for the aGCT-derived KGN, cell line identified 24 genes whose expression significantly differs between the early and stage 3 aGCT. Of these, 16 were more abundantly expressed in the stage 3 aGCT and 8 were higher in the stage 1 tumors. These changes were further examined for the genes which showed the greatest fold change: the cytokine CXCL14, microfibrillar-associated protein 5, insulin-like 3 and desmin. Gene Set Enrichment Analysis identified overexpression of genes on chromosome 7p15 which includes the homeobox A gene locus. The analysis therefore identifies a small number of genes with clearly discriminate patterns of expression arguing that the clinicopathological-derived distinction of the tumor stage is robust, whilst confirming the relative homogeneity of expression for many genes across the cohort and hence of aGCT. The expression profiles do however identify several overexpressed genes in both stage 1 and/or stage 3 aGCT which warrant further study as possible therapeutic targets.