Analysis of menstrual effluent: diagnostic potential for endometriosis

DNA-based cell typing in menstrual effluent identifies cell type variation by sample collection method: toward noninvasive biomarker development for women's health

Menstrual effluent cell profiles have potential as noninvasive biomarkers of female reproductive and gynecological health and disease. We used DNA methylation-based cell type deconvolution (methylation cytometry) to identify cell type profiles in self-collected menstrual effluent. During the second day of their menstrual cycle, healthy participants collected menstrual effluent using a vaginal swab, menstrual cup, and pad. Immune cell proportions were highest in menstrual cup samples, and epithelial cells were highest in swab samples. Our work demonstrates the feasibility and utility of menstrual effluent cell profiling in population-level research using remotely collected samples and DNA methylation.

Endometriosis is not the endometrium: Reviewing the over-representation of eutopic endometrium in endometriosis research

As a heterogenous disease with likely multiple pathogeneses and as-yet-undefined subtypes, progress in endometriosis treatment is currently limited by a lack of appropriate models and cohorts for research. Almost half of all publicly available datasets labelled as 'endometriosis' do not represent true disease as they are based on eutopic endometrium. Eutopic endometrial cells and tissues are frequently being used to represent endometriotic lesions, despite the unequivocal differences at both the tissue and cellular levels. As preclinical endometriosis research increases, it is important that the unique cellular and molecular profiles of endometrium and endometriosis are distinguished. Whilst each of these biospecimens can provide invaluable information to better understand disease aetiology and identify targets for diagnosis and treatment, it is imperative that the appropriate biospecimen and model are used to answer the relevant research question because endometriosis is not the endometrium.

Methylation Risk Score Modelling in Endometriosis: Evidence for Non-Genetic DNA Methylation Effects in a Case-Control Study

Endometriosis is a chronic gynaecological disease characterised by endometrial-like tissue found external to the uterus. While several studies have reported strong evidence of a genetic contribution to the disease, studies on the environmental impact on endometriosis are limited. DNA methylation (DNAm) can be influenced by genetic and environmental factors and serves as a useful biological marker of the effects of genetic and environmental exposures on complex diseases. This study aims to develop a methylation risk score (MRS) for endometriosis to increase the power to detect DNAm signals associated with the disease and enhance our understanding of the pathogenesis of the disease. Endometrial methylation and genotype data from 318 controls and 590 cases were analysed. MRSs were developed using several different models. MRS performances were evaluated by splitting samples into training and test sets based on independent cohort institutions, and the area under the receiver-operator curve (AUC) was calculated. The maximum AUC obtained from the best-performing MRS is 0.6748, derived from 746 DNAm sites. The classification performance of MRS and polygenic risk score (PRS) combined was consistently higher than PRS alone. This study demonstrates that there are DNAm signals independent of common genetic variants associated with endometriosis.

Endometriosis and autoimmunity

Endometriosis is a female-specific chronic condition that affects 1 in 10 women and other individuals with a uterus worldwide with common symptoms that include pelvic pain and infertility. Reliable and effective non-invasive biomarkers for endometriosis do not exist, and therefore currently a diagnosis of endometriosis requires direct visualization of lesions at surgery. Similarly, few safe and effective management strategies exist for endometriosis, with hormonal interventions and surgery only providing temporary symptom control. The development of endometriosis involves the implantation and proliferation of ectopic endometrial cells which triggers local and systemic inflammation and fibrosis. While multiple genetic, environmental, and lifestyle factors appear to influence the natural history of endometriosis, chronic inflammation is a hallmark feature associated with development and progression of the disease. Data further shows that endometriosis commonly co-occurs with autoimmune diseases, adding evidence that immune dysfunction likely contributes to the pathogenesis of this disorder. Specific innate and adaptive immune system drivers of endometriosis remain to be identified and additional research is needed to elucidate the mechanistic underpinnings of this debilitating disease. In this narrative review, we discuss the shared biological mechanisms and plausible immune-related connections between endometriosis and autoimmunity.

Endometriosis in Adolescence: A Narrative Review of the Psychological and Clinical Implications

Endometriosis is a chronic, inflammatory condition where endometrial-like tissue grows outside the uterus, affecting around 10% of women of reproductive age. This condition is associated with debilitating symptoms, including dysmenorrhea, dyspareunia, chronic pelvic pain, fatigue, and infertility. Adolescents with endometriosis face unique challenges, as the disease is often misdiagnosed or undiagnosed for an average of 7-10 years due to its complex and multifactorial nature. Consequently, patients frequently suffer from worsening symptoms and significant psychological distress, including anxiety, depression, and social withdrawal. While there is no definitive cure for endometriosis, treatment approaches typically involve hormonal therapies, lifestyle adjustments (such as diet and exercise), and psychological support. Recent studies emphasize the profound impact of endometriosis on the mental health of adolescents, highlighting the need for a more holistic treatment approach that integrates both medical and psychological care. This narrative review explores the psychological and psychosocial effects of endometriosis in adolescents, examining the biological and psychological mechanisms linking the disease to mental health outcomes. It also discusses current therapeutic strategies, such as cognitive behavioral therapy, mindfulness, and peer support, and underscores the importance of early diagnosis and multidisciplinary care to mitigate both the physical and emotional burdens of the condition. This integrated approach is critical in improving the overall well-being and quality of life for adolescents living with endometriosis.

Molecular Basis of Impaired Decidualization in the Eutopic Endometrium of Endometriosis Patients

Endometriosis is a chronic gynecological disorder characterized by the presence of endometrial tissue outside the uterine cavity. A common feature of this pathology is the impaired decidualization of endometrial stromal cells, a critical process that prepares the uterus for embryo implantation. This decidualization defect has been mechanistically linked to progesterone resistance in endometriotic lesions. However, the presence and underlying mechanisms of decidualization defects in the eutopic endometrium of women with endometriosis remain controversial. The aim of the present study is to integrate and discuss molecular evidence from both in vivo and in vitro studies examining decidualization alterations in the eutopic endometrium of patients with endometriosis. Multiple studies have demonstrated impaired decidualization in the eutopic endometrium of women with endometriosis. These alterations have been reported on multiple genes, signaling pathways, and epigenetic processes. However, additional functional studies are warranted to elucidate whether these decidualization defects directly contribute to endometriosis-associated infertility. A better understanding of the decidualization process and its dysregulation in endometriosis will not only advance the development of targeted fertility treatments but also facilitate the design of more effective therapeutic strategies for managing this chronic condition.

Mapping Human Uterine Disorders Through Single-Cell Transcriptomics

Disruptions in uterine tissue function contribute to disorders such as endometriosis, adenomyosis, endometrial cancer, and fibroids, which all significantly impact health and fertility. Advances in transcriptomics, particularly single-cell RNA sequencing, have revolutionized uterine biological research by revealing the cellular heterogeneity and molecular mechanisms underlying disease states. Single-cell RNA sequencing and spatial transcriptomics have mapped endometrial and myometrial cellular landscapes, which helped to identify critical cell types, signaling pathways, and phase-specific dynamics. Said transcriptomic technologies also identified stromal and immune cell dysfunctions, such as fibroblast-to-myofibroblast transitions and impaired macrophage activity, which drive fibrosis, chronic inflammation, and lesion persistence in endometriosis. For endometrial cancer, scRNA-seq uncovered tumor microenvironmental complexities, identifying cancer-associated fibroblast subtypes and immune cell profiles contributing to progression and therapeutic resistance. Similarly, studies on adenomyosis highlighted disrupted signaling pathways, including Wnt and VEGF, and novel progenitor cell populations linked to tissue invasion and neuroinflammation, while single-cell approaches characterized smooth muscle and fibroblast subpopulations in uterine fibroids, elucidating their roles in extracellular matrix remodeling and signaling pathways like ERK and mTOR. Despite challenges such as scalability and reproducibility, single-cell transcriptomic approaches may have potential applications in biomarker discovery, therapeutic target identification, and personalized medicine in gynecological disorders.

Surface Molecular Markers for the Isolation of Viable Fibroblast Subpopulations in the Female Reproductive Tract: A Comprehensive Review

Advancements in single-cell analyzis technologies, particularly single-cell RNA sequencing (scRNA-seq) and Fluorescence-Activated Cell Sorting (FACS), have enabled the analyzis of cellular diversity by providing resolutions that were not available previously. These methods enable the simultaneous analyzis of thousands of individual transcriptomes, facilitating the classification of cells into distinct subpopulations, based on transcriptomic differences, adding a new level of complexity to biomolecular and medical research. Fibroblasts, despite being one of the most abundant cell types in the human body and forming the structural backbone of tissues and organs, remained poorly characterized for a long time. This is largely due to the high morphological similarity between different types of fibroblasts and the lack of specific markers to identify distinct subpopulations. Once thought to be cells responsible solely for the synthesis of extracellular matrix (ECM) components, fibroblasts are now recognized as active participants in diverse physiological processes, including inflammation and antimicrobial responses. However, defining the molecular profile of fibroblast subpopulations remains a significant challenge. In this comprehensive review, which is based on over two thousand research articles, we focus on the identification and characterization of fibroblast subpopulations and their specific surface markers, with an emphasis on their potential as molecular targets for selective cell isolation. By analyzing surface markers, alongside intra- and extracellular protein profiles, we identified multiple fibroblast subtypes within the female reproductive system. These subtypes exhibit distinct molecular signatures and functional attributes, shaped by their anatomical localization and the surrounding physiological or pathological conditions. Our findings underscore the heterogeneity of fibroblasts and their diverse roles in various biological contexts. This improved understanding of fibroblast subpopulations paves the way for innovative diagnostic and therapeutic strategies, offering the potential for precision targeting of specific fibroblast subsets in clinical applications.

Plant bioactive compounds driven microRNAs (miRNAs): A potential source and novel strategy targeting gene and cancer therapeutics

Irrespective of medical technology improvements, cancer ranks among the leading causes of mortality worldwide. Although numerous cures and treatments exist, creating alternative cancer therapies with fewer adverse side effects is vital. Since ancient times, plant bioactive compounds have already been used as a remedy to heal cancer. These plant bioactive compounds and their anticancer activity can also deregulate the microRNAs (miRNAs) in the cancerous cells. Therefore, the deregulation of miRNAs in cancer cells by plant bioactive compounds and the usage of the related miRNA could be a promising approach for cancer cure, mainly to prevent cancer and overcome chemotherapeutic side effect problems. Hence, this review highlights the function of plant bioactive compounds as an anticancer agent through the underlying mechanism that alters the miRNA expression in cancer cells, ultimately leading to apoptosis. Moreover, this review provides insight into using plant bioactive compounds -driven miRNAs as an anticancer agent to develop miRNA-based cancer gene therapy. They can be the potential resource for gene therapy and novel strategies targeting cancer therapeutics.

Menstrual Blood as a Non-Invasive Alternative for Monitoring Vitamin Levels

Background/Objectives: Menstrual blood has recently emerged as a novel specimen for diagnostics, offering a non-invasive alternative to traditional blood testing methods. Despite the importance of vitamins and monitoring their levels in preventative healthcare measures, the feasibility of measuring them in menstrual blood has yet to be explored. In this study, we aimed to assess the potential of using menstrual blood for determining vitamin levels by comparing their levels in menstrual blood to those in matched capillary blood samples. Methods: A prospective, monocentric, observational study was conducted with healthy, reproductive-aged voluntary participants. Menstrual blood was collected from 30 participants using a menstrual cup, and the corresponding capillary blood samples were obtained using a finger prick. The samples were transferred to dried blood spot (DBS) cards and analyzed using mass spectrometry to determine vitamin levels. Statistical analyses were performed to compare menstrual blood vitamin A and D levels, and hemoglobin, to those in capillary blood. Results: The vitamin levels could be ascertained from the menstrual blood, and were observed to significantly correlate with those from the capillary blood for both vitamin A (r = 0.77, p < 0.001) and vitamin D (r = 0.66, p < 0.001), despite being statistically different. Conclusions: The results of this pilot study demonstrate the potential utility of menstrual blood in estimating vitamin A and D levels, illustrating the prospect of a non-invasive menstrual blood-based vitamin test following larger clinical and analytical validation studies.

Alterations in the expression of serum-derived exosome-enclosed inflammatory microRNAs in Covid-19 patients

Introduction

MicroRNAs in exosomes play a role in biological processes such as inflammation and Epithelial-mesenchymal transition (EMT). In EMT, epithelial cells undergo phenotypic changes and become similar to mesenchymal cells. EMT increases the invasion and metastasis of cancer cells. We aimed to evaluate the expression levels of miRNA-21, miRNA-218, miRNA-155, and miRNA-10b, which are effective in the pathway of inflammation and EMT in serum-derived exosome of COVID-19 patients.

Method

Blood samples were taken from 30 patients with COVID-19 and five healthy individuals as a control group. After separating the serum from the collected blood, the exosomes were purified from the serum. Relative expression of microRNAs was measured by real-time PCR method.

Results

The relative expression of miRNA-21, miRNA-218, and miRNA-155 in serum-derived exosomes of patients with COVID-19 had a significant increase (p < 0.0001). Also, the relative expression of miRNA-10b was significantly increased in the patient group (p < 0.01), but the changes in the expression level of miRNA-10b were not as significant as the changes in the expression level of other microRNAs.

Conclusion

miRNA-21, miRNA-218, miRNA-155, and miRNA-10b are involved in the pathogenesis of COVID-19 disease, and their transmission by exosomes leads to pathogenic lesions and problems in other parts of the body.

Gene expression of aromatase, SF-1, and HSD17B2 in menstrual blood as noninvasive diagnostic biomarkers for endometriosis

OBJECTIVE

Endometriosis diagnostic delays are still encountered due to the lack of a reliable, noninvasive diagnostic test. Besides, menstrual blood is a relatively untapped field for diagnostics, yet it provides a readily accessible source for investigating common gynecological conditions. In the present study, we aim to evaluate the expression levels of menstrual blood aromatase, SF-1, and HSD17B2 from women with and without endometriosis and their diagnostic performance.

METHODS

A total of 40 subjects participated in this study, including 20 patients from each endometriosis and non-endometriosis group. The endometriosis group comprised patients with proven endometriosis confirmed by pathological diagnosis and pelvic ultrasound examination, then requiring endometrial biopsy determined by the clinicians. The non-endometriosis group consisted of women who had primary and secondary infertility and underwent endometrial examination without any visible endometriosis lesion. The menstrual blood and eutopic endometrial tissue of enrolled subjects were collected, and the relative expression of the genes was performed by quantitative real-time polymerase chain reaction (qPCR). ROC curve was used to evaluate the diagnostic efficacy of aromatase, SF-1, and HSD17B2.

RESULTS

We found significantly higher expressions of aromatase, SF-1, and HSD17B2 in the menstrual blood of the endometriosis group compared to non-endometriosis (P < 0.05). In contrast, examination of eutopic endometrial tissue of both groups only found significant in HSD17B2 (P < 0.05), while aromatase and SF-1 showed no statistically significant variance. The Area Under Curve (AUC) of aromatase, SF-1, and HSD17B2 in the menstrual blood was 0.977, 0.862, and 0.807, respectively. The optimal cutoff value was determined to be >1.63 (sensitivity = 95 % and specificity = 90 %) for aromatase, >1.71 (sensitivity = 90 % and specificity = 80 %) for SF-1, and >1.83 (sensitivity = 80 % and specificity = 75 %) for HSD17B2.

CONCLUSION

Our study showed that aromatase, SF-1, and HSD17B2 in the menstrual blood solidly discriminate between endometriosis and non-endometriosis patients with high diagnostic accuracy. However, further confirmation in larger cohorts is required to validate the reliability of these biomarkers to endometriosis.

Quercetin enhances decidualization through AKT-ERK-p53 signaling and supports a role for senescence in endometriosis

BACKGROUND

Patients with endometriosis suffer with chronic pelvic pain and infertility, and from the lack of pharmacologic therapies that consistently halt disease progression. Differences in the endometrium of patients with endometriosis vs. unaffected controls are well-documented. Specifically, shed endometrial tissues (delivered to the pelvic cavity via retrograde menstruation) reveal that a subset of stromal cells exhibiting pro-inflammatory, pro-fibrotic, and pro-senescence-like phenotypes is enhanced in endometriosis patients compared to controls. Additionally, cultured biopsy-derived endometrial stromal cells from endometriosis patients exhibit impaired decidualization, a defined differentiation process required for human embryo implantation and pregnancy. Quercetin, a senolytic agent, shows therapeutic potential for pulmonary fibrosis, a disorder attributed to senescent pulmonary fibroblasts. In rodent models of endometriosis, quercetin shows promise, and quercetin improves decidualization in vitro. However, the exact mechanisms are not completely understood. Therefore, we investigated the effects of quercetin on menstrual effluent-derived endometrial stromal cells from endometriosis patients and unaffected controls to define the signaling pathways underlying quercetin's effects on endometrial stromal cells.

METHODS

Menstrual effluent-derived endometrial stromal cells were collected and cultured from unaffected controls and endometriosis patients and then, low passage cells were treated with quercetin (25 µM) under basal or standard decidualization conditions. Decidualization responses were analyzed by measuring the production of IGFBP1 and PRL. Also, the effects of quercetin on intracellular cAMP levels and cellular oxidative stress responses were measured. Phosphokinase arrays, western blotting, and flow cytometry methods were performed to define the effects of quercetin on various signaling pathways and the potential mechanistic roles of quercetin.

RESULTS

Quercetin significantly promotes decidualization of control- and endometriosis-endometrial stromal cells. Quercetin substantially reduces the phosphorylation of multiple signaling molecules in the AKT and ERK1/2 pathways, while enhancing the phosphorylation of p53 and total p53 levels. Furthermore, p53 inhibition blocks decidualization while p53 activation promotes decidualization. Finally, we provide evidence that quercetin increases apoptosis of endometrial stromal cells with a senescent-like phenotype.

CONCLUSIONS

These data provide insight into the mechanisms of action of quercetin on endometrial stromal cells and warrant future clinical trials to test quercetin and other senolytics for treating endometriosis.

Investigating Menstruation and Adverse Pregnancy Outcomes: Oxymoron or New Frontier? A Narrative Review

Not discounting the important foetal or placental contribution, the endometrium is a key determinant of pregnancy outcomes. Given the inherently linked processes of menstruation, pregnancy and parturition with the endometrium, further understanding of menstruation will help to elucidate the maternal contribution to pregnancy. Endometrial health can be assessed via menstrual history and menstrual fluid, a cyclically shed, easily and non-invasively accessible biological sample that represents the distinct, heterogeneous composition of the endometrial environment. Menstrual fluid has been applied to the study of endometriosis, unexplained infertility and early pregnancy loss; however, it is yet to be examined regarding adverse pregnancy outcomes. These adverse outcomes, including preeclampsia, foetal growth restriction (FGR), spontaneous preterm birth and perinatal death (stillbirth and neonatal death), lay on a spectrum of severity and are often attributed to placental dysfunction. The source of this placental dysfunction is largely unknown and may be due to underlying endometrial abnormalities or endometrial interactions during placentation. We present existing evidence for the endometrial contribution to adverse pregnancy outcomes and propose that a more comprehensive understanding of menstruation can provide insight into the endometrial environment, offering great potential value as a diagnostic tool to assess pregnancy risk. As yet, this concept has hardly been explored.

Diagnostic Value of Menstrual Blood Lipidomics in Endometriosis: A Pilot Study

Endometriosis is a prevalent chronic inflammatory disease characterized by a considerable delay between initial symptoms and diagnosis through surgery. The pressing need for a timely, non-invasive diagnostic solution underscores the focus of current research efforts. This study examines the diagnostic potential of the menstrual blood lipidome. The lipid profile of 39 samples (23 women with endometriosis and 16 patients in a control group) was acquired using reverse-phase high-performance liquid chromatography-mass spectrometry with LipidMatch processing and identification. Profiles were normalized based on total ion counts. Significant differences in lipids were determined using the Mann-Whitney test. Lipids for the diagnostic model, based on logistic regression, were selected using a combination of variance importance projection filters and Akaike information criteria. Levels of ceramides, sphingomyelins, cardiolipins, triacylglycerols, acyl- and alkenyl-phosphatidylethanolamines, and alkenyl-phosphatidylcholines increased, while acyl- and alkyl-phosphatidylcholines decreased in cases of endometriosis. Plasmenylphosphatidylethanolamine PE P-16:0/18:1 and cardiolipin CL 16:0_18:0_22:5_22:6 serve as marker lipids in the diagnostic model, exhibiting a sensitivity of 81% and specificity of 85%. The diagnostic approach based on dried spots of menstrual blood holds promise as an alternative to traditional non-invasive methods for endometriosis screening.

miR-4443 Contained Extracellular Vesicles: A Factor for Endometriosis Progression by PI3K/AKT/ACSS2 Cascade in-vitro

Introduction

Endometriosis (EM) is an estrogen-dependent benign gynecologic disease affecting approximately 10% of reproductive-age women with a high recurrence rate, but lacks reliable biomarkers. No previous studies have investigated the possible use of extracellular vesicle (EV)-associated micro RNAs (miRNAs) from menstrual blood (MB) as candidate diagnostic or prognostic markers of EM.

Methods

Specimens were obtained from endometriosis and non-endometriosis patients at the International Peace Maternity and Child Health Hospital in Shanghai. Microarray was used to screen differentially expressed miRNAs among peritoneal fluid (PF), fallopian tube fluid (FF), and MB. Dual-luciferase reporter gene assay was carried out to verify the relationship between miR-4443 and ACSS2. Cell proliferation and Transwell invasion assays were performed in vitro after intervention on miR-4443 and ACSS2 in hEM15A human endometrial stromal cells and primary human endometrial stromal cells (hESCs). Spearman correlation analysis, receiver operating characteristic (ROC) curve analysis, and survival analysis were applied to clinical data, including severity of symptoms and relapse of EM among EM patients.

Results

EV-associated miR-4443 was abundant in MB of endometriosis patients. ACSS2 knockdown and miR-4443 overexpression promoted cell proliferation and migration via the PI3K/AKT pathway. miR-4443 levels in MB-EVs were positively correlated with the degree of dyspareunia (r=0.64; P<0.0001) and dysmenorrhea (r=0.42; P<0.01) in the endometriosis group. ROC curve analyses showed an area under the curve (AUC) of 0.741 (95% CI 0.624-0.858; P<0.05) for miR-4443 and an AUC of 0.929 (95% CI 0.880-0.978; P<0.05) for the combination of miR-4443 and dysmenorrhea.

Conclusion

MB-derived EV-associated miR-4443 might participate in endometriosis development, thus providing a new candidate biomarker for the noninvasive prediction of endometriosis recurrence.

Menstrual Blood Donation for Endometriosis Research: A Cross-Sectional Survey on Women's Willingness and Potential Barriers

An anonymous online survey in French was used to assess if endometriosis patients would be as ready as unaffected women to donate their menstrual blood for biological research on endometriosis and evaluate potential barriers to such donation. It was distributed in September 2022 by social media and two mailing lists, including a French patient organization. The questionnaire assessed participant age and brief medical history (hormonal contraception, endometriosis diagnosis, type of endometriosis), menstrual experience (menstrual blood abundance, dysmenorrhea), and whether participants would donate menstrual blood. Women who self-declared with an established endometriosis diagnosis versus no endometriosis were compared. Seven hundred seventy-eight women answered the survey. Among women with menstruation (n = 568), 78% are willing to donate menstrual blood for research. Importantly, this proportion was higher in women who declared having an established endometriosis diagnosis (83%, n = 299) compared to self-declared unaffected women (68%, n = 134, p < 0.001). The previous use of a menstrual cup and dysmenorrhea were significantly associated with the willingness to donate menstrual blood, while the use of hormonal contraception was significantly associated with an unwillingness to donate. Only the previous use of the menstrual cup had a predictive value for menstrual blood donation. No significant relationship was observed between menstrual blood donation and age, heavy menstrual bleeding and in endometriosis patients, endometriosis subtypes. In conclusion, women affected or not by endometriosis are largely willing to donate their menstrual blood for research on endometriosis, dysmenorrhea is not a barrier for donation, and women who use a menstrual cup are the more likely to donate.

Gastrointestinal Myoelectrical Activity (GIMA) Biomarker for Noninvasive Diagnosis of Endometriosis

Background/Objectives: Endometriosis represents substantial direct and indirect healthcare costs impacted by an absence of uniformly accurate, non-invasive diagnostic tools. We endeavored to demonstrate gastrointestinal myoelectrical activity (GIMA) biomarkers, unique to endometriosis, will allow non-invasive, uniformly accurate diagnosis or exclusion of endometriosis. Methods: Prospective open-label comparative study of 154 patients, age ≥ 18, with or without diagnosed endometriosis. Population included 62 non-endometriosis controls (Cohort 1), 43 subjects with surgically/histologically confirmed endometriosis (Cohort 2), and 49 subjects with abdominal pain and negative imaging (Cohort 3). Non-invasive electroviscerography (EVG) recorded GIMA biomarkers from three abdominal electrodes before and 30 min post water load protocol. Cohort 2 had postoperative EVG and Cohort 3 had preoperative EVG. Calculated specificity, sensitivity, negative predictive value (NPV), positive predictive value (PPV), and predictive probability or C-statistic used univariate, multivariate, linear, and logistical regression analyses of the area under the curve (AUC) at all frequency and time points, including age and pain covariants. Results: The non-endometriosis cohort differed significantly from the endometriosis cohorts (p < 0.001) for median (IQR) and AUC percent frequency distribution of power at baseline, 10 min, 20 min, and 30 min post water load at all frequency ranges: 15-20 cpm, 30-40 cpm, and 40-50 cpm. The endometriosis cohorts were statistically similar (p > 0.05). GIMA biomarker threshold scoring demonstrated 95%/91% sensitivity and PPV, 96%/95% specificity and NPV, and a C-statistic of >99%/98%, respectively, for age subsets. GIMA biomarkers in Cohort 3 predicted 47/49 subjects positive and 2/49 negative for endometriosis, confirmed surgically. Hormonal therapy, surgical stage, nor pain score affected diagnostic accuracy. Conclusions: EVG with GIMA biomarker detection distinguished participants with and without endometriosis based upon endometriosis-specific GIMA biomarkers threshold scoring.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

The involvement of RNA N6-methyladenosine and histone methylation modification in decidualization and endometriosis-associated infertility

Defective decidualization of endometrial stromal cells (ESCs) in endometriosis (EM) patients leads to inadequate endometrial receptivity and EM-associated infertility. Hypoxia is an inevitable pathological process of EM and participates in deficient decidualization of the eutopic secretory endometrium. Enhancer of zeste homology 2 (EZH2) is a methyltransferase which catalyses H3K27Me3, leading to decreased expression levels of target genes. Although EZH2 expression is low under normal decidualization, it is abundantly increased in the eutopic secretory endometrium of EM and is induced by hypoxia. Chromatin immunoprecipitation-PCR results revealed that decidua marker IGFBP1 is a direct target of EZH2, partially explaining the increased levels of histone methylation modification in defected decidualization of EM. To mechanism controlling this, we examined the effects of hypoxia on EZH2 and decidualization. EZH2 mRNA showed decreased m6 A modification and increased expression levels under hypoxia and decidualization combined treatment. Increased EZH2 expression was due to the increased expression of m6 A demethylase ALKBH5 and decreased expression of the m6 A reader protein YTHDF2. YTHDF2 directly bind to the m6 A modification site of EZH2 to promote EZH2 mRNA degradation in ESCs. Moreover, selective Ezh2 depletion in mouse ESCs increased endometrial receptivity and improved mouse fertility by up-regulating decidua marker IGFBP1 expression. This is the first report showing that YTHDF2 can act as a m6 A reader to promote decidualization by decreasing the stability of EZH2 mRNA and further increasing the expression of IGFBP1 in ESCs. Taken together, our findings highlight the critical role of EZH2/H3K27Me3 in decidualization and reveal a novel epigenetic mechanism by which hypoxia can suppress EM decidualization by decreasing the m6 A modification of EZH2 mRNA.

DIA-based analysis of the menstrual blood proteome identifies association between CXCL5 and IL1RN and endometriosis

Endometriosis is a gynecological disease related to menstruation that affects nearly 10% of reproductive-age women. However, so far, there are no reliable diagnostic biomarkers for endometriosis, causing a delay in diagnosis of 6.7 ± 6.2 years. Menstrual blood is a non-invasive source of endometrial tissue that can be analyzed for biomarkers of endometriosis. In this study, menstrual blood samples were collected from women with (n = 8) and without (n = 8) endometriosis. Data Independent Acquisition (DIA)-based mass spectrometry and bioinformatic analysis were used to quantify and identify differentially expressed proteins (DEPs) using the thresholds of fold change >1.5 and P value <0.05. A total of 95 DEPs were identified in menstrual blood from women with endometriosis compared to women without endometriosis, of which 64 were up-regulated and 31 were down-regulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to functionally annotate DEPs. Protein-protein interaction (PPI) network analysis was then conducted to identify hub genes and the MCODE plugin placed CXCL1, CXCL3, CXCL5, CCL18, and IL1RN in the most significant cluster network. The expression of the above candidate proteins was confirmed by enzyme-linked immunosorbent assay (ELISA), among which CXCL5 and IL1RN protein expression was increased in patients with endometriosis, indicating that CXCL5 and IL1RN in menstrual blood may be useful biomarkers to diagnose endometriosis from non-invasive samples. SIGNIFICANCE: Endometriosis is a common gynecological disease that causes discomfort in many women. Unfortunately, the diagnosis of endometriosis is frequently delayed due to a lack of reliable non-invasive biomarkers. To our knowledge, this is the first time that DIA-MS was used to characterize the proteome and identify the differentially expressed proteins in menstrual blood from women with endometriosis. The results, as confirmed by ELISA, showed that CXCL5 and IL1RN protein expression is significantly increased in patients with endometriosis, indicating that these proteins can be used as biomarkers for endometriosis. This study contributes to the identification of putative endometriosis biomarkers from non-invasive samples and lays the groundwork for future research into the roles of CXCL5 and IL1RN in the pathogenesis of endometriosis.

Endometriosis in the era of precision medicine and impact on sexual and reproductive health across the lifespan and in diverse populations

Endometriosis is a common estrogen-dependent disorder wherein uterine lining tissue (endometrium) is found mainly in the pelvis where it causes inflammation, chronic pelvic pain, pain with intercourse and menses, and infertility. Recent evidence also supports a systemic inflammatory component that underlies associated co-morbidities, e.g., migraines and cardiovascular and autoimmune diseases. Genetics and environment contribute significantly to disease risk, and with the explosion of omics technologies, underlying mechanisms of symptoms are increasingly being elucidated, although novel and effective therapeutics for pain and infertility have lagged behind these advances. Moreover, there are stark disparities in diagnosis, access to care, and treatment among persons of color and transgender/nonbinary identity, socioeconomically disadvantaged populations, and adolescents, and a disturbing low awareness among health care providers, policymakers, and the lay public about endometriosis, which, if left undiagnosed and under-treated can lead to significant fibrosis, infertility, depression, and markedly diminished quality of life. This review summarizes endometriosis epidemiology, compelling evidence for its pathogenesis, mechanisms underlying its pathophysiology in the age of precision medicine, recent biomarker discovery, novel therapeutic approaches, and issues around reproductive justice for marginalized populations with this disorder spanning the past 100 years. As we enter the next revolution in health care and biomedical research, with rich molecular and clinical datasets, single-cell omics, and population-level data, endometriosis is well positioned to benefit from data-driven research leveraging computational and artificial intelligence approaches integrating data and predicting disease risk, diagnosis, response to medical and surgical therapies, and prognosis for recurrence.

Biopsy-free profiling of the uterine immune system in patients with recurrent pregnancy loss and unexplained infertility

RESEARCH QUESTION

What are the differences in menstrual blood lymphocytes between controls, patients with recurrent pregnancy loss (RPL) and patients with unexplained infertility (uINF)?

DESIGN

Prospective study including 46 healthy controls, 28 RPL and 11 uINF patients. A feasibility study compared lymphocyte compositions of endometrial biopsies and menstrual blood collected during the first 48 h of menstruation in seven controls. In all patients, peripheral and menstrual blood from the first and subsequent 24 h were analysed separately by flow cytometry, focusing on the main lymphocyte populations and natural killer (NK) cell subsets.

RESULTS

The first 24 h of menstrual blood resembles the uterine immune milieu as tested by endometrial biopsy. RPL patients showed significantly higher menstrual blood CD56+ NK cell numbers than controls (mean ± SD: 31.13 ± 7.52% versus 36.73 ± 5.4%, P = 0.002). Menstrual blood CD56dimCD16bright NK cells within the CD56+ NK cell population were decreased in RPL (16.34 ± 14.65%, P = 0.011) and uINF (15.7 ± 5.91%, P = 0.02) patients versus control (20.42 ± 11.53%). uINF patients had the lowest menstrual blood CD3+ T cell counts (38.81 ± 5.04%, control versus uINF: P = 0.01) and cytotoxicity receptors NKp46 and NKG2D on CD56brightCD16dim cells were higher in uINF (68.12 ± 11.84%, P = 0.006; 45.99 ± 13.83%, P = 0.01, respectively) and RPL (NKp46: 66.21 ± 15.36%, P = 0.009) patients versus controls. RPL and uINF patients had higher peripheral CD56+ NK cell counts versus controls (11.42 ± 4.05%, P = 0.021; 12.86 ± 4.29%, P = 0.009 versus 8.4 ± 3.5%).

CONCLUSIONS

Compared with controls, RPL and uINF patients had a different menstrual blood-NK-subtype profile, indicating an altered cytotoxicity. In future studies, this non-invasive analysis might enable identification and monitoring of patients receiving immunomodulatory medications.

Endometrial Origins of Stillbirth (EOS), a case-control study of menstrual fluid to understand and prevent preterm stillbirth and associated adverse pregnancy outcomes: study protocol

INTRODUCTION

Current research aimed at understanding and preventing stillbirth focuses almost exclusively on the role of the placenta. The underlying origins of poor placental function leading to stillbirth, however, remain poorly understood. There is evidence demonstrating that the endometrial environment in which the embryo implants impacts not only the establishment of pregnancy but also the development of some pregnancy outcomes. Menstrual fluid has recently been applied to the study of menstrual disorders such as heavy menstrual bleeding or endometriosis, however, it has great potential in the study of adverse pregnancy outcomes. This study aims to identify differences in menstrual fluid and menstrual cycle characteristics of women who have experienced preterm stillbirth and other associated adverse pregnancy outcomes, compared with those who have not. The association between menstrual fluid composition and menstrual cycle characteristics will also be determined.

METHODS AND ANALYSIS

This is a case-control study of women who have experienced a late miscarriage, spontaneous preterm birth or preterm stillbirth or a pregnancy complicated by placental insufficiency (fetal growth restriction or pre-eclampsia), compared with those who have had a healthy term birth. Cases will be matched for maternal age, body mass index and gravidity. Participants will not currently be on hormonal therapy. Women will be provided with a menstrual cup and will collect their sample on day 2 of menstruation. Primary exposure measures include morphological and functional differences in decidualisation of the endometrium (cell types, immune cell subpopulations and protein composition secreted from the decidualised endometrium). Women will complete a menstrual history survey to capture menstrual cycle length, regularity, level of pain and heaviness of flow.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Monash University Human Research Ethics Committee (27900) on 14/07/2021 and will be conducted in accordance with these conditions. Findings from this study will be disseminated through peer-reviewed publications and conference presentations.

Downregulation of DROSHA: Could It Affect miRNA Biogenesis in Endometriotic Menstrual Blood Mesenchymal Stem Cells?

Menstrual blood mesenchymal stem cells (MenSCs) have gained prominence in the endometriosis scientific community, given their multifunctional roles in regenerative medicine as a noninvasive source for future clinical applications. In addition, changes in post-transcriptional regulation via miRNAs have been explored in endometriotic MenSCs with a role in modulating proliferation, angiogenesis, differentiation, stemness, self-renewal, and the mesenchymal-epithelial transition process. In this sense, homeostasis of the miRNA biosynthesis pathway is essential for several cellular processes and is related to the self-renewal and differentiation of progenitor cells. However, no studies have investigated the miRNA biogenesis pathway in endometriotic MenSCs. In this study, we profiled the expression of eight central genes for the miRNA biosynthesis pathway under experimental conditions involving a two-dimensional culture of MenSCs obtained from healthy women (n = 10) and women with endometriosis (n = 10) using RT-qPCR and reported a two-fold decrease in DROSHA expression in the disease. In addition, miR-128-3p, miR-27a-3p, miR-27b-3p, miR-181a-5p, miR-181b-5p, miR-452-3p, miR-216a-5p, miR-216b-5p, and miR-93-5p, which have been associated with endometriosis, were identified through in silico analyses as negative regulators of DROSHA. Because DROSHA is essential for miRNA maturation, our findings may justify the identification of different profiles of miRNAs with DROSHA-dependent biogenesis in endometriosis.

How to Improve Non-Invasive Diagnosis of Endometriosis with Advanced Statistical Methods

Background and Objectives: Endometriosis is one of the most common gynecological disorders in women of reproductive age. Causing pelvic pain and infertility, it is considered one of the most serious health problems, being responsible for work absences or productivity loss. Its diagnosis is often delayed because of the need for an invasive laparoscopic approach. Despite years of studies, no single marker for endometriosis has been discovered. The aim of this research was to find an algorithm based on symptoms and laboratory tests that could diagnose endometriosis in a non-invasive way. Materials and Methods: The research group consisted of 101 women hospitalized for diagnostic laparoscopy, among which 71 had confirmed endometriosis. Data on reproductive history were collected in detail. CA125 (cancer antigen-125) level and VEGF1(vascular endothelial growth factor 1) were tested in blood samples. Among the used statistical methods, the LASSO regression-a new important statistical tool eliminating the least useful features-was the only method to have significant results. Results: Out of 19 features based on results of LASSO, 7 variables were chosen: body mass index, age of menarche, cycle length, painful periods, information about using contraception, CA125, and VEGF1. After multivariate logistic regression with a backward strategy, the three most significant features were evaluated. The strongest impact on endometriosis prediction had information about painful periods, CA125 over 15 u/mL, and the lowest BMI, with a sensitivity of 0.8800 and a specificity of 0.8000, respectively. Conclusions: Advanced statistical methods are crucial when creating non-invasive tests for endometriosis. An algorithm based on three easy features, including painful menses, BMI level, and CA125 concentration could have an important place in the non-invasive diagnosis of endometriosis. If confirmed in a prospective study, implementing such an algorithm in populations with a high risk of endometriosis will allow us to cover patients suspected of endometriosis with proper treatment.

Comprehensive landscape and future perspectives of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC): Based on a bibliometric analysis

This review aimed to use bibliometric analysis to sort out, analyze and summarize the knowledge foundation and hot topics in the field of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC), and point out future trends to inspire related research and innovation. We used CiteSpace to analyze publication outputs, countries, institutions, authors, journals, references, and keywords. Knowledge foundations, hotspots, and future trends were then depicted. The overall research showed the trend of biomedical-oriented multidisciplinary. Much evidence indicates that lncRNA plays the role of oncogene or tumor suppressor in the occurrence and development of CRC. Besides, many lncRNAs have multiple mechanisms. lncRNAs and metastasis of CRC, lncRNAs and drug resistance of CRC, and the clinical application of lncRNAs in CRC are current research hotspots. Through insight into the development trend of lncRNAs in CRC, this study will help researchers extract hidden valuable information for further research.

Targeted Proteomics Analysis of Staphylococcal Superantigenic Toxins in Menstrual Fluid from Women with Menstrual Toxic Shock Syndrome (mTSS)

Menstrual toxic shock syndrome (mTSS) is a rare life-threatening febrile illness that occurs in women using intravaginal menstrual protection. It is caused by toxic shock syndrome toxin 1 (TSST-1) produced by Staphylococcus aureus, triggering a sudden onset of rash and hypotension, subsequently leading to multiple organ failure. Detecting TSST-1 and S. aureus virulence factors in menstrual fluid could accelerate the diagnosis and improve therapeutic management of mTSS. However, menstrual fluid is a highly complex matrix, making detection of bacterial toxins challenging. Here, we present a mass-spectrometry-based proteomics workflow for the targeted, quantitative analysis of four S. aureus superantigenic toxins in menstrual fluids (TSST-1, SEA, SEC, and SED). This method was applied to characterize toxin levels in menstrual fluids collected from patients with mTSS and healthy women. Toxins were detectable in samples from patients with mTSS and one healthy donor at concentrations ranging from 0 to 0.46 µg/mL for TSST-1, and 0 to 1.07 µg/mL for SEC. SEA and SED were never detected in clinical specimens, even though many S. aureus strains were positive for the corresponding genes. The method presented here could be used to explore toxin production in vivo in users of intravaginal devices to improve the diagnosis, understanding, and prevention of mTSS.

Untargeted metabolomics reveals that multiple reproductive toxicants are present at the endometrium

BACKGROUND

Recent epidemiologic research shows many environmental chemicals exhibit endocrine disrupting effects on the female reproductive system. Few studies have examined exposure at reproductive organs. Our aim was to perform a preliminary untargeted metabolomic characterization of menstrual blood, a novel biofluid, to identify environmental toxins present in the endometrium and evaluate the suitability of this sample type for exposome research.

METHODS

Whole blood menstrual samples were collected from four women using a menstrual cup. Samples were analyzed for small molecules that include both environmental chemicals and endogenous metabolites using untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS). Principal component analysis (PCA) and ANOVA was used to identify differences within and between individuals' menstrual blood metabolomic profiles, and the influence of the sample processing method. To assess the presence of environmental exposures, LC-HRMS chemical profiles were matched to the ToxCast chemical database, which includes 4557 commonly used commercial chemicals. Select compounds were confirmed by comparison to reference standards.

RESULTS

PCA of metabolome profiles showed analysis of menstrual blood samples were highly reproducible, with high variability in detected metabolites between participants and low variability between analytical replicates of an individual's sample. Endogenous metabolites detected in menstrual blood samples achieved good coverage of the human blood metabolome. We found 1748 annotations for environmental chemicals, including suspected reproductive toxicants such as phenols, parabens, phthalates, and organochlorines. Storage temperature for the first 24 h did not significantly influence global metabolomic profiles.

CONCLUSION

Our results show chemical exposures linked to reproductive toxicity and endocrine disruption are present in menstrual blood, a sampling medium for the endometrium.

What Do the Transcriptome and Proteome of Menstrual Blood-Derived Mesenchymal Stem Cells Tell Us about Endometriosis?

Given the importance of menstrual blood in the pathogenesis of endometriosis and the multifunctional roles of menstrual mesenchymal stem cells (MenSCs) in regenerative medicine, this issue has gained prominence in the scientific community. Moreover, recent reviews highlight how robust the integrated assessment of omics data are for endometriosis. To our knowledge, no study has applied the multi-omics approaches to endometriosis MenSCs. This is a case-control study at a university-affiliated hospital. MenSCs transcriptome and proteome data were obtained by RNA-seq and UHPLC-MS/MS detection. Among the differentially expressed proteins and genes, we emphasize ATF3, ID1, ID3, FOSB, SNAI1, NR4A1, EGR1, LAMC3, and ZFP36 genes and MT2A, TYMP, COL1A1, COL6A2, and NID2 proteins that were already reported in the endometriosis. Our functional enrichment analysis reveals integrated modulating signaling pathways such as epithelial-mesenchymal transition (↑) and PI3K signaling via AKT to mTORC1 (↓ in proteome), mTORC1 signaling, TGF beta signaling, TNFA signaling via NFkB, IL6 STAT3 signaling, and response to hypoxia via HIF1A targets (↑ in transcriptome). Our findings highlight primary changes in the endometriosis MenSCs, suggesting that the chronic inflammatory endometrial microenvironment can modulate these cells, providing opportunities for endometriosis etiopathogenesis. Moreover, they identify challenges for future research leveraging knowledge for regenerative and precision medicine in endometriosis.

Single-cell analysis of menstrual endometrial tissues defines phenotypes associated with endometriosis

BACKGROUND

Endometriosis is a common, complex disorder which is underrecognized and subject to prolonged delays in diagnosis. It is accompanied by significant changes in the eutopic endometrial lining.

METHODS

We have undertaken the first single-cell RNA-sequencing (scRNA-Seq) comparison of endometrial tissues in freshly collected menstrual effluent (ME) from 33 subjects, including confirmed endometriosis patients (cases) and controls as well as symptomatic subjects (who have chronic symptoms suggestive of endometriosis but have not been diagnosed).

RESULTS

We identify a unique subcluster of proliferating uterine natural killer (uNK) cells in ME-tissues from controls that is almost absent from endometriosis cases, along with a striking reduction of total uNK cells in the ME of cases (p < 10-16). In addition, an IGFBP1+ decidualized subset of endometrial stromal cells are abundant in the shed endometrium of controls when compared to cases (p < 10-16) confirming findings of compromised decidualization of cultured stromal cells from cases. By contrast, endometrial stromal cells from cases are enriched in cells expressing pro-inflammatory and senescent phenotypes. An enrichment of B cells in the cases (p = 5.8 × 10-6) raises the possibility that some may have chronic endometritis, a disorder which predisposes to endometriosis.

CONCLUSIONS

We propose that characterization of endometrial tissues in ME will provide an effective screening tool for identifying endometriosis in patients with chronic symptoms suggestive of this disorder. This constitutes a major advance, since delayed diagnosis for many years is a major clinical problem in the evaluation of these patients. Comprehensive analysis of ME is expected to lead to new diagnostic and therapeutic approaches to endometriosis and other associated reproductive disorders such as female infertility.

T helper 17 axis and endometrial macrophage disruption in menstrual effluent provides potential insights into the pathogenesis of endometriosis

OBJECTIVE

To identify immune cells, cytokines, and immune cell transcriptome in the menstrual effluent (ME) of women with endometriosis compared with that of healthy donors.

DESIGN

Live immune cells were isolated from human ME samples and were analyzed by flow cytometry to identify various immune cell populations. Selected cytokines from the same patients were evaluated using multiplex cytokine analyses. The transcriptome of the immune cell population was subsequently profiled using NanoString nCounter's PanCancer Immune panel.

SETTING

Academic institution.

PATIENT(S)

Surgically confirmed endometriosis patients (n = 14) and healthy fertile donors (n = 19).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

In-depth immune cell profiling of ME obtained from women with endometriosis compared with that of healthy donors.

RESULT(S)

ME analysis revealed that the number of T helper 17 (T_H17) cells was significantly lower in patients with endometriosis compared with that of healthy donors; the number of macrophages was also lower (P=.06) in the former. Multiplex cytokine analysis revealed significantly lower transforming growth factor α in the ME "serum" of patients with endometriosis. Transcriptomic analysis of CD45⁺ cells revealed 47 differentially expressed genes, mainly associated with the T_H17 axis (IL10, IL23A, and IL6), as well as genes associated with macrophage signaling/activation (CD74, CD83, CXCL16, and CCL3).

CONCLUSION(S)

We demonstrate for the first time that the levels of T_H17 axis, macrophages, and transforming growth factor α were altered in the ME of women with endometriosis compared with that of healthy donors. These findings shed light on the potential immune pathways that could partly explain the pathogenesis and progression of endometriosis. Future large-scale studies on ME samples are warranted to exploit the use of these markers to study the pathogenesis of endometriosis.

Uterine Natural Killer Cells: A Rising Star in Human Pregnancy Regulation

Uterine natural killer (uNK) cells are an immune subset located in the uterus. uNK cells have distinct tissue-specific characteristics compared to their counterparts in peripheral blood and lymphoid organs. Based on their location and the pregnancy status of the host, uNK cells are classified as endometrial NK (eNK) cells or decidua NK (dNK) cells. uNK cells are important in protecting the host from pathogen invasion and contribute to a series of physiological processes that affect successful pregnancy, including uterine spiral artery remodeling, fetal development, and immunity tolerance. Abnormal alterations in uNK cell numbers and/or impaired function may cause pregnancy complications, such as recurrent miscarriage, preeclampsia, or even infertility. In this review, we introduce recent advances in human uNK cell research under normal physiological or pathological conditions, and summarize their unique influences on the process of pregnancy complications or uterine diseases. Finally, we propose the potential clinical use of uNK cells as a novel cellular immunotherapeutic approach for reproductive disorders.

Uterine bleeding: how understanding endometrial physiology underpins menstrual health

Menstruation is a physiological process that is typically uncomplicated. However, up to one third of women globally will be affected by abnormal uterine bleeding (AUB) at some point in their reproductive years. Menstruation (that is, endometrial shedding) is a fine balance between proliferation, decidualization, inflammation, hypoxia, apoptosis, haemostasis, vasoconstriction and, finally, repair and regeneration. An imbalance in any one of these processes can lead to the abnormal endometrial phenotype of AUB. Poor menstrual health has a negative impact on a person's physical, mental, social, emotional and financial well-being. On a global scale, iron deficiency and iron deficiency anaemia are closely linked with AUB, and are often under-reported and under-recognized. The International Federation of Gynecology and Obstetrics have produced standardized terminology and a classification system for the causes of AUB. This standardization will facilitate future research endeavours, diagnosis and clinical management. In a field where no new medications have been developed for over 20 years, emerging technologies are paving the way for a deeper understanding of the biology of the endometrium in health and disease, as well as opening up novel diagnostic and management avenues.

A combination of immune cell types identified through ensemble machine learning strategy detects altered profile in recurrent pregnancy loss: a pilot study

OBJECTIVE

To compare the immunologic profiles of peripheral and menstrual blood (MB) of women who experience recurrent pregnancy loss and women without pregnancy complications.

DESIGN

Explorative case-control study. Cross-sectional assessment of flow cytometry-derived immunologic profiles.

SETTING

Academic medical center.

PATIENT(S)

Women who experienced more than 2 consecutive miscarriages.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Flow cytometry-based immune profiles of uterine and systemic immunity (recurrent pregnancy loss, n = 18; control, n = 14) assessed by machine learning classifiers in an ensemble strategy, followed by recursive feature selection.

RESULT(S)

In peripheral blood, the combination of 4 cell types (nonswitched memory B cells, CD8+ T cells, CD56bright CD16- natural killer [NKbright] cells, and CD4+ effector T cells) classified samples correctly to their respective cohort. The identified classifying cell types in peripheral blood differed from the results observed in MB, where a combination of 6 cell types (Ki67+CD8+ T cells, (Human leukocyte antigen-DR+) regulatory T cells, CD27+ B cells, NKbright cells, regulatory T cells, and CD24HiCD38Hi B cells) plus age allowed for assigning samples correctly to their respective cohort. Based on the combination of these features, the average area under the curve of a receiver operating characteristic curve and the associated accuracy were >0.8 for both sample sources.

CONCLUSION(S)

A combination of immune subsets for cohort classification allows for robust identification of immune parameters with possible diagnostic value. The noninvasive source of MB holds several opportunities to assess and monitor reproductive health.

Lipid Alterations in Early-Stage High-Grade Serous Ovarian Cancer

Epithelial ovarian cancer (OC) ranks first in the number of deaths among diseases of the female reproductive organs. Identification of OC at early stages is highly beneficial for the treatment but is highly challenging due to the asymptomatic or low-symptom disease development. In this study, lipid extracts of venous blood samples from 41 female volunteers, including 28 therapy-naive patients with histologically verified high-grade serous ovarian cancer at different stages (5 patients with I-II stages; 23 patients with III-IV stages) and 13 apparently healthy women of reproductive age, were profiled by high-performance liquid chromatography mass spectrometry (HPLC-MS). Based on MS signals of 128 differential lipid species with statistically significant level variation between the OC patients and control group, an OPLS-DA model was developed for the recognition of OC with 100% sensitivity and specificity R 2 = 0.87 and Q2 = 0.80. The second OPLS-DA model was developed for the differentiation between I-II OC stages and control group with R 2 = 0.97 and Q2 = 0.86 based on the signal levels of 108 differential lipid species. The third OPLS-DA model was developed for the differentiation between I-II OC stages and III-IV stages based on the signal levels of 99 differential lipid species. Various lipid classes (diglycerides, triglycerides, phosphatidylchlorines, ethanolamines, sphingomyelins, ceramides, phosphatidylcholines and phosphoinositols) in blood plasma samples display distinctly characteristic profiles in I-II OC, which indicates the possibility of their use as marker oncolipids in diagnostic molecular panels of early OC stages. Our results suggest that lipid profiling by HPLC-MS can improve identification of early-stage OC and thus increase the efficiency of treatment.

Overexpression of miR-200b-3p in Menstrual Blood-Derived Mesenchymal Stem Cells from Endometriosis Women

The key relationship between Sampson's theory and the presence of mesenchymal stem cells in the menstrual flow (MenSCs), as well as the changes in post-transcriptional regulatory processes as actors in the etiopathogenesis of endometriosis, are poorly understood. No study to date has investigated the imbalance of miRNAs in MenSCs related to the disease. Thus, through literature and in silico analyses, we selected four predicted miRNAs as regulators of EGR1, SNAI1, NR4A1, NR4A2, ID1, LAMC3, and FOSB involved in pathways of apoptosis, angiogenesis, response to steroid hormones, migration, differentiation, and cell proliferation. These genes are frequently overexpressed in the endometriosis condition in our group studies. They were the trigger for the miRNAs search. Therefore, a case-control study was conducted with MenSCs of women with and without endometriosis (ten samples per group). Crossing information obtained from the STRING, PubMed, miRPathDB, miRWalk, and DIANA TOOLS databases, we chose to explore the expression of miR-21-5p, miR-100-5p, miR-143-3p, and miR-200b-3p by RT-qPCR. We found an upregulation of the miR-200b-3p in endometriosis MenSCs (P = 0.0207), with a 7.93-fold change (ratio of geometric means) compared to control. Overexpression of miR-200b has been associated with increased cell proliferation, stemness, and accentuated mesenchymal-epithelial transition process in eutopic endometrium of endometriosis. We believe that dysregulated miR-200b-3p may establish primary changes in the MenSCs, thus favoring tissue implantation at the ectopic site.

Endometrial Stem/Progenitor Cells–Their Role in Endometrial Repair and Regeneration

The human endometrium is a remarkable tissue, undergoing ~450 cycles of proliferation, differentiation, shedding (menstruation), repair, and regeneration over a woman's reproductive lifespan. Post-menstrual repair is an extremely rapid and scar-free process, with re-epithelialization of the luminal epithelium completed within 48 h of initiation of shedding. Following menstruation, the functionalis grows from the residual basalis layer during the proliferative phase under the influence of rising circulating estrogen levels. The regenerative capacity of the endometrium is attributed to stem/progenitor cells which reside in both the epithelial and stromal cell compartments of the basalis layer. Finding a definitive marker for endometrial epithelial progenitors (eEPCs) has proven difficult. A number of different markers have been suggested as putative progenitor markers including, N-cadherin, SSEA-1, AXIN2, SOX-9 and ALDH1A1, some of which show functional stem cell activity in in vitro assays. Each marker has a unique location(s) in the glandular epithelium, which has led to the suggestion that a differentiation hierarchy exists, from the base of epithelial glands in the basalis to the luminal epithelium lining the functionalis, where epithelial cells express different combinations of markers as they differentiate and move up the gland into the functionalis away from the basalis niche. Perivascular endometrial mesenchymal stem cells (eMSCs) can be identified by co-expression of PDGFRβ and CD146 or by a single marker, SUSD2. This review will detail the known endometrial stem/progenitor markers; their identity, location and known interactions and hierarchy across the menstrual cycle, in particular post-menstrual repair and estrogen-driven regeneration, as well as their possible contributions to menstruation-related disorders such as endometriosis and regeneration-related disorder Asherman's syndrome. We will also highlight new techniques that allow for a greater understanding of stem/progenitor cells' role in repair and regeneration, including 3D organoids, 3D slice cultures and gene sequencing at the single cell level. Since mouse models are commonly used to study menstruation, repair and regeneration we will also detail the mouse stem/progenitor markers that have been investigated in vivo.

Pattern of hospital antibiotic use in term neonates using WHO Access, Watch and Reserve Classification (AWaRe)

BACKGROUND AND OBJECTIVE

Pakistan has high neonatal mortality rate and antibiotic utilization data in hospitalized term neonates from Pakistan is lacking. The study aimed to determine the pattern of hospital antibiotic use in term neonates using World Health Organization (WHO) Access, Watch, and Reserve classification (AWaRe).

METHODS

This cross-sectional chart review study was conducted at the neonatal unit of Pediatric Medicine Department of University Hospital over a period of one year from 1^st January 2020 to 31^st December 2020. Hospitalized full term newborns up to 28-days of life, of either gender were consecutively included in the study. Data on demographic characteristics, admission diagnoses and antibiotic prescribed (class, agent and duration) were extracted from clinical charts. Descriptive statistics in the form of mean ± SD and frequency and percentages were calculated.

RESULTS

A total of 2276 term neonates consisting of 69% (n=1570) males were included in the study. Antibiotic prescription rate was 92.8%. Most common reason for admission was birth asphyxia (36.1%) followed by sepsis (33%). Most commonly prescribed antibiotic Ampicillin (84%) belonged to Access group of WHO - AWaRe classification. More than 97% of prescriptions were two or more antimicrobial combinations belonging to Watch group. Ampicillin and Cefoperazone was the most commonly prescribed (42.8%) two drug combination. Meropenem and vancomycin was prescribed to 20% of the neonates - mostly for sepsis and pneumonia. Mortality rate was 7.7% in current study.

CONCLUSION

High antibiotic prescription rate particularly from Watch-group is demonstrated in this study. There is high need of antimicrobial stewardship program in neonatal units.

Transcriptome-Based Analysis Reveals Therapeutic Effects of Resveratrol on Endometriosis in aRat Model

INTRODUCTION

Endometriosis (EMs) is associated with severe chronic pelvic pain and infertility and the development of improved EMs treatment options is an ongoing focus. In this study, we investigated the effects of resveratrol on EMs and analyzed transcriptional changes in the lesions of model rats before and after resveratrol treatment.

METHODS

We established arat model of endometriosis through the trans-implantation of endometrial fragments to the peritoneal wall and then used resveratrol as treatment. We then analyzed the results using RNA sequencing of the lesion tissues of each of the model rats before resveratrol treatment and the reduced lesion tissues after the treatment. Examinations of anatomy, biochemistry, immunohistochemical staining and flow cytometry examinations were also conducted. Other trans-implanted rats were also given sham treatments as sham-treatment control and other untrans-implanted rats served as sham-operation controls.

RESULTS

In addition to the obvious lesions observed in the model rats, there were significant differences in the glucose tolerance, macrophage M1/M2 polarization, and adipocyte sizes between the treated model rats and sham (control) rats. Resveratrol treatment in the model rats showed significant efficacy and positive therapeutic effect. Transcriptional analysis showed that the effects of resveratrol on the endometriosis model rats were manifested by alterations in the PPAR, insulin resistance, MAPK and PI3K/Akt signaling pathways. Correspondingly, changes in PPARγ activation, M1/M2 polarization and lipid metabolism were also detected after resveratrol treatment.

DISCUSSION

Our study revealed that resveratrol treatment displayed efficient therapeutic effects for EMs model rats, probably through its important roles in anti-inflammation, immunoregulation and lipid-related metabolism regulation.

Reduced frequency of perforin-positive CD8+ T cells in menstrual effluent of endometriosis patients

Endometriosis is a widespread disease and commonly reduces the life quality of those affected. Scientific literature indicates different underlying immunological changes. Frequently examined tissues are peripheral blood, endometrial tissue and peritoneal fluid. Yet, knowledge on immunological differences in menstrual effluent (ME) is scarce. In this study, between January 2018 and August 2019, 12 women with endometriosis (rASRM classification: stages I-IV) and 11 healthy controls were included. ME was collected using menstrual cups and venous blood samples (PB) were taken. Mononuclear cells were obtained from ME (MMC) and PB (PBMC) and analyzed using flow cytometry. Concentrations of cell adhesion molecules (ICAM-I and VCAM-I) and cytokines (IL-6, IL-8 and TNF-α) were measured using ELISA. CD8 + T cells obtained from ME were significantly less often perforin-positive in women with endometriosis compared to healthy controls. A comparison between MMC and PBMC revealed that MMC contained significantly less T cells and more B cells. The CD4/CD8 ratio was significantly higher in MMC, and Tregs were significantly less frequently in MMC. In ME, T cells and NK cells expressed significantly more CD69. NK cells obtained from ME were predominantly CD56^bright/CD16^dim and had a lower frequency of perforin + cells compared to PBMC NK cells. Moreover, ICAM-1 plasma levels were significantly reduced in women with endometriosis compared to healthy controls. In conclusion, CD8 + T cells obtained from the ME were significantly less perforin-positive in endometriosis patients indicating a reduced cytotoxic potential. MMC are distinctively different from PBMC and, thus, seem to be of endometrial origin.

Menstrual fluid endometrial stem/progenitor cell and supernatant protein content: cyclical variation and indicative range

STUDY QUESTION

Does natural variation exist in the endometrial stem/progenitor cell and protein composition of menstrual fluid across menstrual cycles in women?

SUMMARY ANSWER

Limited variation exists in the percentage of some endometrial stem/progenitor cell types and abundance of selected proteins in menstrual fluid within and between a cohort of women.

WHAT IS KNOWN ALREADY

Menstrual fluid is a readily available biofluid that can represent the endometrial environment, containing endometrial stem/progenitor cells and protein factors. It is unknown whether there is natural variation in the cellular and protein content across menstrual cycles of individual women, which has significant implications for the use of menstrual fluid in research and clinical applications.

STUDY DESIGN, SIZE, DURATION

Menstrual fluid was collected from 11 non-pregnant females with regular menstrual cycles. Participants had not used hormonal medications in the previous 3 months. Participants collected menstrual fluid samples from up to five cycles using a silicone menstrual cup worn on Day 2 of menstrual bleeding.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Menstrual fluid samples were centrifuged to separate soluble proteins and cells. Cells were depleted of red blood cells and CD45+ leucocytes. Menstrual fluid-derived endometrial stem/progenitor cells were characterized using multicolour flow cytometry including markers for endometrial stem/progenitor cells N-cadherin (NCAD) and stage-specific embryonic antigen-1 (SSEA-1) (for endometrial epithelial progenitor cells; eEPC), and sushi domain containing-2 (SUSD2) (for endometrial mesenchymal stem cells; eMSC). The clonogenicity of menstrual fluid-derived endometrial cells was assessed using colony forming unit assays. Menstrual fluid supernatant was analyzed using a custom magnetic Luminex assay.

MAIN RESULTS AND THE ROLE OF CHANCE

Endometrial stem/progenitor cells are shed in menstrual fluid and demonstrate clonogenic properties. The intraparticipant agreement for SUSD2+ menstrual fluid-derived eMSC (MF-eMSC), SSEA-1+ and NCAD+SSEA-1+ MF-eEPC, and stromal clonogenicity were moderate-good (intraclass correlation; ICC: 0.75, 0.56, 0.54 and 0.52, respectively), indicating limited variability across menstrual cycles. Endometrial inflammatory and repair proteins were detectable in menstrual fluid supernatant, with five of eight (63%) factors demonstrating moderate intraparticipant agreement (secretory leukocyte protein inhibitor (SLPI), lipocalin-2 (NGAL), lactoferrin, follistatin-like 1 (FSTL1), human epididymis protein-4 (HE4); ICC ranges: 0.57-0.69). Interparticipant variation was limited for healthy participants, with the exception of key outliers of which some had self-reported menstrual pathologies.

LARGE SCALE DATA

N/A. There are no OMICS or other data sets relevant to this study.

LIMITATIONS, REASONS FOR CAUTION

The main limitations to this research relate to the difficulty of obtaining menstrual fluid samples across multiple menstrual cycles in a consistent manner. Several participants could only donate across <3 cycles and the duration of wearing the menstrual cup varied between 4 and 6 h within and between women. Due to the limited sample size used in this study, wider studies involving multiple consecutive menstrual cycles and a larger cohort of women will be required to fully determine the normal range of endometrial stem/progenitor cell and supernatant protein content of menstrual fluid. Possibility for selection bias and true representation of the population of women should also be considered.

WIDER IMPLICATIONS OF THE FINDINGS

Menstrual fluid is a reliable source of endometrial stem/progenitor cells and related endometrial proteins with diagnostic potential. The present study indicates that a single menstrual sample may be sufficient in characterizing a variety of cellular and protein parameters across women's menstrual cycles. The results also demonstrate the potential of menstrual fluid for identifying endometrial and menstrual abnormalities in both research and clinical settings as a non-invasive method for assessing endometrial health.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Australian National Health and Medical Research Council to C.E.G. (Senior Research Fellowship 1024298 and Investigator Fellowship 1173882) and to J.E. (project grant 1047756), the Monash IVF Research Foundation to C.E.G. and the Victorian Government's Operational Infrastructure Support Program. K.A.W., M.L.D.-T., S.G.S. and J.E. declare no conflicts of interest. C.E.G. reports grants from NHMRC, during the conduct of the study; grants from EndoFound USA, grants from Ferring Research Innovation, grants from United States Department of Defence, grants from Clue-Utopia Research Foundation, outside the submitted work. CEF reports grants from EndoFound USA, grants from Clue-Utopia Research Foundation, outside the submitted work.

Bioluminescent imaging in induced mouse models of endometriosis reveals differences in four model variations

Our understanding of the aetiology and pathophysiology of endometriosis remains limited. Disease modelling in the field is problematic as many versions of induced mouse models of endometriosis exist. We integrated bioluminescent imaging of 'lesions' generated using luciferase-expressing donor mice. We compared longitudinal bioluminescence and histology of lesions, sensory behaviour of mice with induced endometriosis and the impact of the gonadotropin-releasing hormone antagonist Cetrorelix on lesion regression and sensory behaviour. Four models of endometriosis were tested. We found that the nature of the donor uterine material was a key determinant of how chronic the lesions were, as well as their cellular composition. The severity of pain-like behaviour also varied across models. Although Cetrorelix significantly reduced lesion bioluminescence in all models, it had varying impacts on pain-like behaviour. Collectively, our results demonstrate key differences in the progression of the 'disease' across different mouse models of endometriosis. We propose that validation and testing in multiple models, each of which may be representative of the different subtypes/heterogeneity observed in women, should become a standard approach to discovery science in the field of endometriosis.

A Rare Case of Endometriosis of the Small Bowel

Endometriosis of the small bowel is a rare clinical event. The clinical condition presents with vague abdominal symptoms and is usually not diagnosed acutely, unless clinicians have a high index of suspicion. Most patients are diagnosed after multiple clinical encounters. We present a case of endometriosis causing small bowel obstruction diagnosed postsurgically.

Endometrial stem/progenitor cells in menstrual blood and peritoneal fluid of women with and without endometriosis

RESEARCH QUESTION

Are endometrial stem/progenitor cells shed into uterine menstrual blood (UMB) and the peritoneal cavity in women with and without endometriosis during menstruation?

DESIGN

Women with (n = 32) and without endometriosis (n = 29) at laparoscopy (total 61), carried out during the menstrual (n = 41) and non-menstrual phase (n = 20) were recruited. The UMB, peritoneal fluid and peripheral blood were analysed by clonogenicity assay and flow cytometry to quantify the concentrations of endometrial clonogenic cells, SUSD2⁺ mesenchymal stem cells (eMSC) and N-cadherin⁺ epithelial progenitor cells (eEPC).

RESULTS

Clonogenic endometrial cells, eMSC and eEPC were found in most UMB samples at similar concentrations in women with and without endometriosis. In contrast, 62.5% of women with endometriosis and 75.0% without (controls) had clonogenic cells in peritoneal fluid samples during menses. The eMSC were present in the peritoneal fluid of 76.9% of women with endometriosis and 44.4% without, and eEPC were found in the peritoneal fluid of 60.0% of women with and 25.0% without endometriosis during menses. Median clonogenic, eMSC and eEPC concentrations in peritoneal fluid were not significantly different between groups. More clonogenic cells persisted beyond the menstrual phase in the peritoneal fluid of women with endometriosis (menstrual 119/ml [0-1360/ml] versus non-menstrual 8.5/ml [0-387/ml]; P = 0.277) compared with controls (menstrual 76.5/ml [1-1378/ml] versus non-menstrual 0/ml [0-14/ml]; P = 0.0362). No clonogenic endometrial cells were found in peripheral blood.

CONCLUSIONS

Clonogenic endometrial cells, SUSD2⁺ eMSC and N-cadherin⁺ eEPC are present in UMB and the peritoneal fluid of women with and without endometriosis. Further study of the function of these cells may shed light on the cellular origins of endometriosis.

Identification of suitable reference genes for mesenchymal stem cells from menstrual blood of women with endometriosis

It has been suggested that menstrual blood-derived mesenchymal stem/stromal cells (MenMSCs) are associated with the etiopathogenesis of endometriosis and considerable effort has been invested in searching for target genes and deciphering associated molecular pathways. However, reference gene stability for proper reproducible normalization in the analyses of the expression data validation is still unexplored in this experimental context. Therefore, in this exploratory study, we used stringent case and control selection criteria and collected menstrual blood from women with a laparoscopic diagnosis of advanced endometriosis and from fertile women without endometriosis. We tested for the first time the stability of 32 candidate reference genes to achieve increased accuracy and reliable results in the quantification of gene expression and direct future experiments using reverse transcription-quantitative PCR (RT-qPCR) in MenMSCs for endometriosis studies. Using the RefFinder web tool, we recommend the EIF2B1 and POP4 reference genes for the normalization of RT-qPCR data in study designs similar to ours. Furthermore, we suggest avoiding the commonly used GAPDH and ACTB reference genes as they are unstable. This high-visibility study is capable of directing different experimental designs as MenMSCs are derived from a minimally invasive tissue source with multifunctional roles in regenerative medicine.

Cellular Origins of Endometriosis: Towards Novel Diagnostics and Therapeutics

Endometriosis remains an enigmatic disease of unknown etiology, with delayed diagnosis and poor therapeutic options. This review will discuss the cellular, physiological, and genomic evidence of Sampson's hypothesis of retrograde menstruation as a cause of pelvic endometriosis and as the basis of phenotypic heterogeneity of the disease. We postulate that collaborative research at the single cell level focused on unlocking the cellular, physiological, and genomic mechanisms of endometriosis will be accompanied by advances in personalized diagnosis and therapies that target unique subtypes of endometriosis disease. These advances will address the clinical conundrums of endometriosis clinical care—including diagnostic delay, suboptimal treatments, disease recurrence, infertility, chronic pelvic pain, and quality of life. There is an urgent need to improve outcomes for women with endometriosis. To achieve this, it is imperative that we understand which cells form the lesions, how they arrive at distant sites, and what factors govern their ability to survive and invade at ectopic locations. This review proposes new research avenues to address these basic questions of endometriosis pathobiology that will lay the foundations for new diagnostic tools and treatment pathways.