Exploring Epithelial-Mesenchymal Transition Signals in Endometriosis Diagnosis and In Vitro Fertilization Outcomes

The effect of endometriosis on oocyte quality: mechanisms, diagnosis and treatment

Endometriosis significantly impacts the physical and mental health of women of reproductive age. While some patients can achieve pregnancy through surgery or in vitro fertilization (IVF), many still struggle with IVF failure due to poor oocyte quality. This presents a major clinical challenge that requires immediate attention. The causes of oocyte quality decline in endometriosis patients are diverse and have not yet been definitively identified. Furthermore, effective diagnostic mechanisms and therapeutic strategies remain elusive. To provide possible clinical solutions to improve pregnancy rates in patients with endometriosis, this review evaluates the current literature on the impact of endometriosis on oocyte quality, the possible mechanisms and management strategies of endometriosis leading to poor oocyte quality.

Endometrial Dysbiosis: A Possible Association with Estrobolome Alteration

BACKGROUND/OBJECTIVES

Microbiota modification at the endometrial level can favor gynecological diseases and impair women's fertility. The overgrowth of pathogen microorganisms is related to the contemporary alteration of estrogen-metabolizing bacteria, including β-glucuronidase, thereby enhancing estrogen-related inflammatory states and decreasing anti-inflammatory cells. The possible connection between estrobolome impairment and gynecological diseases has been suggested in animal models. Nevertheless, in humans, coherent evidence on the estrobolome alteration and functionality of the female reproductive tract is still lacking. The objective of this study was to explore alterations in estrogen-related signaling and the putative link with endometrial dysbiosis.

METHODS

Women with infertility and repeated implantation failure (RIF, N = 40) were enrolled in order to explore the putative link between estrogen metabolism and endometrial dysbiosis. Endometrial biopsies were used to measure inflammatory and growth factor molecules. β-glucuronidase enzyme activity and estrogen receptor (ER) expression were also assessed.

RESULTS

Herein, increased levels of inflammatory molecules (i.e., IL-1β and HIF-1α) and decreased levels of the growth factor IGF-1 were found in the endometrial biopsies of patients presenting dysbiosis compared to eubiotic ones. β-glucuronidase activity and the expression of ERβ were significantly enhanced in patients in the dysbiosis group. Interestingly, Lactobacilli abundance was inversely related to β-glucuronidase activity and to ERβ expression, thus suggesting that an alteration of the estrogen-activating enzyme may affect the expression of ERs as well.

CONCLUSIONS

Overall, these preliminary data suggested a link between endometrial dysbiosis and estrobolome impairment as possible synergistic contributing factors to women infertility and RIF.

An Approach to Improve Endometrial Receptivity: Is It Beneficial to Flush The Uterine Cavity with Follicular Fluid and Granulosa Cells? A Phase III Randomised Clinical Trial

BACKGROUND

The follicular fluid (FF) of mature oocytes contains a high concentration of growth factors and cytokines that have the potential to influence implantation in either a paracrine or autocrine manner. During the physiological processes of ovulation, FF enters the fallopian tubes in conjunction with the oocyte. The purpose of this study is to evaluate implantation and clinical pregnancy rates following uterine flushing with FF and granulosa cells in infertile women with moderate male factor infertility after ovum retrieval for intracytoplasmic sperm injection (ICSI).

MATERIALS AND METHODS

This phase III randomised clinical trial enrolled 140 women with moderate male factor infertility who intended to undergo ICSI at Royan Infertility Clinic (Tehran, Iran). A computer-generated program and opaque sealed envelopes were used to randomly allocate patients to either an intervention group (n=70) or a control group (n=70). Participants in the intervention group received 2 ml of clear FF (without blood contamination) from 2 to 3 dominant follicles after oocyte retrieval. The control group only underwent uterine cavity catheterisation.

RESULTS

The intervention group had a clinical pregnancy rate of 38.5% (25/65) compared to the control group [42.9% (27/63); P=0.719] and an implantation rate of 24.1% compared to the control group (27%; P=0.408). These rates did not differ between the groups. There were no statistically significant differences between the intervention and control groups in terms of pregnancy-related complications-ectopic pregnancy, blighted ovum or anembryonic pregnancy, and abortion.

CONCLUSION

Uterine cavity flushing with FF from mature follicles following oocyte retrieval had no effect, either positively or negatively, on clinical pregnancy or implantation rates in women with moderate male factor infertility (registration number: NCT04077970).

Regular exercise delays microvascular endothelial dysfunction by regulating antioxidant capacity and cellular metabolism

Aging is the basis for several unfavorable conditions, including cardiovascular diseases (CVDs). In this sense, regular physical activity (regular PA) has been proven to delay cellular aging and prevent endothelial dysfunction related to CVDs. Despite numerous studies involving athletes, little is known about cellular and molecular mechanisms of regular PA among master athletes. The present study aimed at evaluating the effects of regular PA on local microcirculatory functions in elderly athletes as compared to age-matched sedentary controls. Moreover, molecular/epigenetic mechanisms (nitric oxide, oxidative stress, PGC-1α, SIRT1 and miR29) were also assessed. The results of the present study showed that regular PA significantly increased local blood flow in post-ischemia and post-heating conditions, as well as NO plasma concentrations, denoting a better endothelial function/microcirculatory efficiency. Moreover, athletes presented a greater plasma antioxidant and increased transcriptional levels of the metabolism regulator PGC-1α. Finally, regular PA enhanced plasma level of SIRT1 and miR29, suggested as epigenetic regulators of redox balance and cellular metabolism. In addition, stimulated local blood flow was directly related to plasma antioxidant capacity, and SIRT1 and miR29 levels. Overall, our data confirm the beneficial effects of regular PA on the cardiovascular profile in elderly athletes and shed light on molecular signals involved in the positive adaptations to exercise.

The Comparative Invasiveness of Endometriotic Cell Lines to Breast and Endometrial Cancer Cell Lines

Endometriosis is an invasive condition that affects 10% of women (and people assigned as female at birth) worldwide. The purpose of this study was to characterize the relative invasiveness of three available endometriotic cell lines (EEC12Z, iEc-ESCs, tHESCs) to cancer cell lines (MDA-MB-231, SW1353 and EM-E6/E7/TERT) and assess whether the relative invasiveness was consistent across different invasion assays. All cell lines were subjected to transwell, spheroid drop, and spheroid-gel invasion assays, and stained for vimentin, cytokeratin, E-Cadherin and N-Cadherin to assess changes in expression. In all assays, endometriotic cell lines showed comparable invasiveness to the cancer cell lines used in this study, with no significant differences in invasiveness identified. EEC12Z cells that had invaded within the assay periods showed declines in E-Cadherin expression compared to cells that had not invaded within the assay period, without significant changes in N-Cadherin expression, which may support the hypothesis that an epithelial-to-mesenchymal transition is an influence on the invasiveness shown by this peritoneal endometriosis cell line.

Dismissal informs the priorities of endometriosis patients in New Zealand

Introduction

Endometriosis is a common condition with average delays to diagnosis in New Zealand of almost 9 years.

Methods

In total, 50 endometriosis patients participated in anonymous, asynchronous, online group discussions about their priorities, and their experiences with the development of symptoms, seeking a diagnosis, and receiving appropriate treatment.

Results

Higher subsidy of care was the top change endometriosis patients wanted, followed by more research funding. When asked to choose whether research should be focused on improving diagnosis or improving treatment methods, the results were evenly split. Within this cohort, patients highlighted that they did not know the difference between normal menstrual discomfort and pathological endometriotic pain. If, upon seeking help, medical practitioners classified their symptoms as "normal," these dismissals could instill doubt in patients, which made it more difficult for them to continue to seek a diagnosis and effective treatments. Patients who did not express dismissal had a significantly shorter delay from symptom onset to diagnosis of 4.6 ± 3.4 years vs. 9.0 ± 5.2 years.

Conclusion

Doubt is a frequent experience for endometriosis patients in New Zealand, which was reinforced by some medical practitioners who were dismissive of their pain and thus prolonged the patient's delay to diagnosis.

The effect of individual oocyte matched follicular fluid oxidant, antioxidant status, and pro- and anti-inflammatory cytokines on IVF outcomes of patients with diminished ovarian reserve

Oocyte matched follicular fluid oxidant, antioxidant status, and pro- and anti-inflammatory cytokine levels were assessed to reveal a possible effect of local-intrafollicular levels of these markers on the individual oocyte with its quality, ability to achieve fertilization, further embryo development, and pregnancy. A cross-sectional study of infertile women with diminished ovarian reserve undergoing antagonist protocol in vitro fertilization (IVF); in the form of ICSI, and fresh single embryo transfer were included. When follicular fluid was collected, each ovarian follicle was aspirated independently, and each follicular fluid was collected into a separate test tube to match it with a single cumulus-oocyte complex obtained from the same follicle. Oocyte matched follicular fluid samples and blood specimens were taken from the participants. Relationships of total antioxidant status, total oxidant status, oxidative stress index, total thiol, interleukin (IL)-6, IL-8, and IL-10 levels of each follicle with oocyte grade, grade of transferred embryos, and pregnancy rate of a given follicle were assessed. A total of 23 infertile women with diminished ovarian reserve and 79 individual follicles of these women were assessed. Serum total oxidant status level of metaphase II (MII) group was significantly lower than non-MII group (P < .001). Follicular fluid IL-6 level of MII group was significantly lower than non-MII group (P = .005). Follicular fluid IL-8 value was significantly low with positive pregnancy results (P < .001). Serum oxidative stress status and follicular fluid pro-inflammatory cytokines were associated with IVF outcomes. This unique study might guide IVF practice with the aim of developing and establishing more effective therapeutic strategies and choosing embryos with more potential for success.

The Expression of TGF-β1, SMAD3, ILK and miRNA-21 in the Ectopic and Eutopic Endometrium of Women with Endometriosis

The molecular pathogenesis of endometriosis has been associated with pathological alterations of protein expression via disturbances in homeostatic genes, miRNA expression profiles, and signaling pathways that play an essential role in the epithelial-mesenchymal transition (EMT) process. TGF-β1 has been hypothesized to play a key role in the development and progression of endometriosis, but the activation of a specific mechanism via the TGF-β-SMAD-ILK axis in the formation of endometriotic lesions is poorly understood. The aim of this study was to assess the expression of EMT markers (TGF-β1, SMAD3, ILK) and miR-21 in ectopic endometrium (ECE), in its eutopic (EUE) counterpart, and in the endometrium of healthy women. The expression level of the tested genes and miRNA was also evaluated in peripheral blood mononuclear cells (PBMC) in women with and without endometriosis. Fifty-four patients (n = 54; with endometriosis, n = 29, and without endometriosis, n = 25) were enrolled in the study. The expression levels (RQ) of the studied genes and miRNA were evaluated using qPCR. Endometriosis patients manifested higher TGF-β1, SMAD3, and ILK expression levels in the eutopic endometrium and a decreased expression level in the ectopic lesions in relation to control tissue. Compared to the endometrium of healthy participants, miR-21 expression levels did not change in the eutopic endometrium of women with endometriosis, but the RQ was higher in their endometrial implants. In PBMC, negative correlations were found between the expression level of miR-21 and the studied genes, with the strongest statistically significant correlation observed between miR-21 and TGF-β1. Our results suggest the loss of the endometrial epithelial phenotype defined by the differential expression of the TGF-β1, SMAD3 and ILK genes in the eutopic and ectopic endometrium. We concluded that the TGF-β1-SMAD3-ILK signaling pathway, probably via a mechanism related to the EMT, may be important in the pathogenesis of endometriosis. We also identified miR-21 as a possible inhibitor of this TGF-β1-SMAD3-ILK axis.

Oxidative Stress-Related Signaling Pathways Predict Oocytes' Fertilization In Vitro and Embryo Quality

Oocyte development and fertilization are largely influenced by the microenvironment of the follicular fluid (FF), and the exploration of its molecular/metabolic composition may help in improving in vitro fertilization (IVF) outcomes. Here, the concentrations of molecules related to oxidative stress/inflammation were measured in FF from follicles at oocyte retrieval during IVF. Here, the FF antioxidant potential was correlated with the number of retrieved/mature oocytes and the number of fertilized ones. FF collected from the follicles of normal fertilized oocytes presented an elevated antioxidant capability, lower levels of pro-inflammatory molecules (i.e., IL-6, IL-8, IL-12, TGF-β, and HIF-1α), and a higher IL-10 concentration. FF samples from follicles at oocyte retrieval that resulted in top-quality embryos displayed a peculiar antioxidant capability and a further decrease in proinflammatory molecules when compared with FF, giving rise to poor-quality embryos. Finally, pro-inflammatory molecules were lower and accompanied by a high antioxidant capability in samples giving rise to successful embryo implantation. The antioxidant capability and IL-10 displayed a good predictive ability for fertilization and embryo quality. Overall, our data showed the great influence of oxidative stress on the oocytes' fertilization, and shed light on the importance of controlling the inflammatory and oxidative status of FF to obtain good-quality embryos with significant implantation potential.

Plasma and Peritoneal Fluid ZEB Levels in Patients with Endometriosis and Infertility

Zinc finger E-box-binding homeobox 1 (ZEB1) and zinc finger E-box-binding homeobox 2 (ZEB2) are transcription factors that regulate epithelial−mesenchymal transformation (EMT). The aim of this study was to compare levels of ZEB1 and ZEB2 in the peritoneal fluid and plasma between patients with and without endometriosis in order to assess their utility in the diagnostic process. Plasma and peritoneal fluid samples were collected from 50 patients with and 48 without endometriosis during planned surgical procedures in eight clinical centers. Quantitative ZEB1 and ZEB2 levels analyses were performed using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). No significant differences were observed in ZEB1 levels in any of the subanalyses nor any differences regarding ZEB2 levels between patients with and without endometriosis. Plasma ZEB2 levels were significantly higher among patients with infertility compared to fertile women (16.07 ± 12.70 ng/L vs. 12.07 ± 11.92 ng/L; p < 0.04). Both ZEB1 and ZEB2 do not seem to have a significant value in the initial diagnosis of endometriosis as a single marker. The differences in ZEB2 plasma levels between patients with and without infertility indicate the possibility of EMT dysregulation in the pathogenesis of adverse fertility outcomes.

The experiences of endometriosis patients with diagnosis and treatment in New Zealand

Endometriosis is a chronically painful, invasive, inflammatory disease, with limited treatment options and long delays to diagnosis, which impacts 10% of females in New Zealand.

Introduction

As part of a larger group discussion study, this paper covers three themes associated with endometriosis patient experiences: intensity of pain, diagnostic tool shortcomings and perspectives of treatment options.

Materials and methods

The goal of this research was the inclusion of patient voices to guide research priorities. In early 2022, 50 New Zealand endometriosis patients participated in anonymous, asynchronous, text-based group discussions on the VisionsLive platform. The patients ranged in age from 18-48. The patients answered 50 questions, 23 text-based and 27 quantitative, and then took part in online group discussions.

Results and discussion

The average age of symptom onset was 15.3 years, while the average delay from symptom onset to a working or surgically confirmed diagnosis was 7.91 years. The top five reported symptoms within the cohort were pain-based, and the participants discussed the many impacts of this pain on their work and education. The four main diagnostic tools employed on this cohort were abdominal ultrasound (72%), transvaginal ultrasound (68%), laparoscopy (82%) and sharing their symptom history with a medical practitioner (88%). The most common emotions patients experienced following receiving a diagnosis of endometriosis were relief (86%), feeling overwhelmed (54%), and anger (32%). The main treatments offered to this cohort were pain relief (96%), laparoscopic surgery (84%) and the combined oral contraceptive pill (80%). Of these three treatments, only laparoscopic surgery was viewed positively by the majority of users, with 67% considering laparoscopy an effective treatment, compared to 46% of users for pain relief, and 25% of users for the combined oral contraceptive pill.

Conclusions

Gathering the voice of patients revealed that long delays to diagnosis and dismissal by medical practitioners frequently manifests as a reaction of relief by patients once diagnosed. Results also showed treatment options such as pain relief and hormonal medications were often considered ineffective, but were routinely offered as the first, or only, options for patients. It is therefore important that both quicker routes to diagnosis and more effective treatment options be developed.

SIRT1 upregulation promotes epithelial-mesenchymal transition by inducing senescence escape in endometriosis

Endometrial epithelial cells carry distinct cancer-associated alterations that may be more susceptible to endometriosis. Mouse models have shown that overexpression of SIRT1 associated with oncogene activation contributes to the pathogenesis of endometriosis, but the underlying reason remains elusive. Here, we used integrated systems biology analysis and found that enrichment of endometrial stromal fibroblasts in endometriosis and their cellular abundance correlated negatively with epithelial cells in clinical specimens. Furthermore, endometrial epithelial cells were characterized by significant overexpression of SIRT1, which is involved in triggering the EMT switch by escaping damage or oncogene-induced induced senescence in clinical specimens and in vitro human cell line models. This observation supports that genetic and epigenetic incident favors endometrial epithelia cells escape from senescence and fuel EMT process in endometriosis, what could be overcome by downregulation of SIRT1.

Endometriosis Is Undervalued: A Call to Action

Endometriosis is an inflammatory chronic pain condition caused by uterine tissue growing outside of the uterus that afflicts at least 11% of women (and people assigned female at birth) worldwide. This condition results in a substantial burden to these women, and society at large. Although endometriosis was first identified over 160 years ago, substantial knowledge gaps remain, including confirmation of the disease's etiology. Research funding for endometriosis is limited, with funding from bodies like the National Institutes of Health (NIH) constituting only 0.038% of the 2022 health budget—for a condition that affects 6.5 million women in the US alone and over 190 million worldwide. A major issue is that diagnosis of endometriosis is frequently delayed because surgery is required to histologically confirm the diagnosis. This delay increases symptom intensity, the risk of central and peripheral sensitization and the costs of the disease for the patient and their nation. Current conservative treatments of presumed endometriosis are pain management and birth control. Both of these methods are flawed and can be entirely ineffective for the reduction of patient suffering or improving ability to work, and neither addresses the severe infertility issues or higher risk of certain cancers. Endometriosis research deserves the funding and attention that befits a disease with its substantial prevalence, effects, and economic costs. This funding could improve patient outcomes by introducing less invasive and more timely methods for diagnosis and treatment, including options such as novel biomarkers, nanomedicine, and microbiome alterations.

Endometrial Dysbiosis Is Related to Inflammatory Factors in Women with Repeated Implantation Failure: A Pilot Study

An abnormal endometrial microbiota has been suggested to impair the process of embryo implantation, thus leading to repeated implantation failure (RIF) in women undergoing in vitro fertilization (IVF). However, the molecular mechanisms linking uterine microbiota and IVF out-comes are still an open question. The aim of this cohort study was to outline the relationship between endometrial microbiota, inflammation and IVF outcomes. To this purpose, endometrial microbiota and selected components of the “cytokine network” were analyzed in women presenting RIF and divided between eubiosis and dysbiosis groups, according to the percentage of endometrial lactobacilli (≥90% or <90%, respectively). The Dysbiosis group presented significantly higher tissue concentrations of the inflammatory markers (IL-6, IL-1β, HIF-1α and COX-2) and significantly lower levels of the anti-inflammatory/well-being factors, IL-10 and IGF-1, with respect to women with eubiosis. Moreover, the Lactobacillus percentage was negatively related to the concentrations of the inflammatory molecules and positively related to IL-10/IGF-1. Interestingly, the number of IVF attempts was directly related to the levels of the inflammatory factors COX-2, IL-1β and HIF-1α in the eubiosis group. Overall, endometrial dysbiosis was demonstrated to be associated with inflammation-related endometrial changes affecting the process of embryo implantation, underlining the importance of assessing uterine microbiota in patients undergoing IVF.