Peritoneal fluid of women with endometriosis reduces SOD1 in bovine oocytes in vitro maturation

Serum trace element levels and activity of enzymes associated with oxidative stress in endometriosis and endometrial cancer

Endometriosis and endometrial cancer are closely related to oxidative stress. However, the direct relationship between copper and zinc levels and oxidative stress in the extracellular and intracellular space remains unclear. The presented study is focused on the determination of serum Zn and Cu levels, glutathione concentration and enzyme activity in three groups: patients diagnosed with endometrial cancer (EC), patients diagnosed with endometriosis (EM), and a healthy control group. Spectrophotometric determination of trace elements revealed that levels of zinc and copper were lower in blood plasma of patients with endometriosis as compared with the other groups; however, there were no significant differences in the Cu/Zn ratio. Furthermore, significantly increased blood serum glutathione levels were detected in both EM and EC groups compared with the control group. While the activity of superoxide dismutase (SOD) was similar across the studied groups, we observed differences in the activity of other enzymes associated with oxidative stress, including glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), between the control group and the EM and EC patients. Additionally, analysis of gene expression based on free circulating mRNA indicated significant differences in the expression of SOD isoenzymes between the patient groups and the control group; expression of GPx isoenzymes was also altered. Obtained results may have potential application in diagnostics as well as monitoring of endometriosis and endometrial cancer.

Glyphosate decreases bovine oocyte quality by inducing oxidative stress and apoptosis

Glyphosate is a universal herbicide with genital toxicity, but the effect of glyphosate on oocytes has not been reported. This study aimed to evaluate the effect of glyphosate (0, 10, 20, 50 and 100 mM) on bovine oocyte in vitro maturation. We showed that 50 mM glyphosate adversely affects the development of bovine oocytes. Exposure of oocytes to 50 mM glyphosate caused an abnormal reduction in oxidative (redox) levels compared with that in the control group, with a significantly higher reactive oxide species level (P < 0.05) and significantly lower glutathione (GSH) expression (P < 0.05). Additionally, the mRNA levels of antioxidant genes (SOD1, SOD2, SIRT2, SIRT3) and the mitochondrial membrane potential (MMP) were significantly reduced (P < 0.05). Furthermore, treatment with 50 mM glyphosate-induced apoptosis, and the mRNA levels of the apoptotic genes Caspase-3 and Caspase-4 were significantly higher than those in the control group (P < 0.05); however, the mRNA level of BAX was significantly higher than that in the control group (P < 0.01). Additionally, the mRNA levels of the anti-apoptotic genes Survivin and BCL-XL were significantly lower than those in the control group (P < 0.05), and oocyte quality was adversely affected. Together, our results confirmed that glyphosate impairs the quality of oocytes by promoting abnormal oocyte redox levels and apoptosis.

Novel therapeutic targets to improve IVF outcomes in endometriosis patients: a review and future prospects

BACKGROUND

Patients with endometriosis often experience infertility and have poor IVF outcomes, with low fertilization and pregnancy rates. Although many theories have tried to explain the mechanisms underlying infertility in these patients, none of them is conclusive.

OBJECTIVE AND RATIONALE

In this review, we discuss the pathologic mechanisms through which endometriosis likely leads to infertility along with the therapeutic options used to date to treat endometriosis-related infertility and, thereby, to improve IVF outcomes in patients with endometriosis.

SEARCH METHODS

We performed a comprehensive literature search of clinical outcomes in endometriosis and the molecular mechanisms contributing to oocyte quality using the PubMed database to identify human and animal studies published from 1992 until September 2020. In total, 123 manuscripts were included.

OUTCOMES

While some theories propose that endometriosis patients may have fertility problems as a result of decreased endometrial receptivity, others reinforce the idea that infertility could be associated with oocyte alterations and lower implantation rates. Single-cell RNA sequencing of oocytes from patients with endometriosis has identified dysregulated mechanisms involved in steroid metabolism and biosynthesis, response to oxidative stress and cell cycle regulation. Dysregulation of these mechanisms could result in the poor IVF outcomes observed in patients with endometriosis. Further, impaired steroidogenesis may directly affect oocyte and embryo quality. Increased oxidative stress in patients with endometriosis also has a detrimental effect on the follicular microenvironment, inducing cell cycle dysregulation in oocytes, poor oocyte quality, and infertility. Moreover, granulosa cells in the context of endometriosis undergo increased apoptosis and have an altered cell cycle that could adversely affect folliculogenesis, oocyte and embryo quality, and IVF outcomes. Endometriosis is also associated with inflammatory damage and impaired angiogenesis, which could be directly correlated with poor IVF outcomes. While therapeutic options using GnRH analogues, progestins and aromatase inhibitors do not improve endometriosis-related infertility, anti-inflammatory agents and antioxidant supplementation could improve oocyte quality as well as implantation and clinical pregnancy rates in patients with endometriosis.

WIDER IMPLICATIONS

Endometriosis is a heterogeneous disease whose pathogenesis is complex and could affect fertility by altering a collection of molecular mechanisms in oocytes. Thus, a single model is not sufficient to describe endometriosis-related infertility. Dysregulation of steroidogenesis, oxidative stress, cell cycle progression, inflammation and angiogenesis in the follicular environment and oocytes in individuals with endometriosis are all possible contributors to endometriosis-related infertility. Therefore, treatments targeting these mechanisms could be therapeutic alternatives to improve IVF outcomes for these patients.

Endometriosis: current challenges in modeling a multifactorial disease of unknown etiology

Endometriosis is a chronic inflammatory hormone-dependent condition associated with pelvic pain and infertility, characterized by the growth of ectopic endometrium outside the uterus. Given its still unknown etiology, treatments usually aim at diminishing pain and/or achieving pregnancy. Despite some progress in defining mode-of-action for drug development, the lack of reliable animal models indicates that novel approaches are required. The difficulties inherent to modeling endometriosis are related to its multifactorial nature, a condition that hinders the recreation of its pathology and the identification of clinically relevant metrics to assess drug efficacy. In this review, we report and comment endometriosis models and how they have led to new therapies. We envision a roadmap for endometriosis research, integrating Artificial Intelligence, three-dimensional cultures and organ-on-chip models as ways to achieve better understanding of physiopathological features and better tailored effective treatments.

Interleukin in endometriosis-associated infertility-pelvic pain: systematic review and meta-analysis

The objective is to study the significance of altered interleukin levels in endometriosis-related infertility or pelvic pain. The present systematic review and meta-analysis includes a discussion on the roles of interleukin in the physiopathology of endometriosis-associated infertility and/or pelvic pain. We included all studies in which interleukins in peritoneal fluid, follicular fluid or serum from patients were measured and that correlated the findings with either peritoneal or deep endometriosis-associated infertility or pelvic pain. For the meta-analysis, we selected studies on the following cytokines: interleukin-1 (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8). Endometriosis is a chronic inflammatory disease. Inflammatory processes clearly participate in the etiology of endometriosis. Cytokines are mediators of inflammation, and increase in their concentration in plasma or other body fluids signals the presence and extent of tissue lesions. A number of studies have reported on the association between higher cytokine levels and progression or maintenance of endometriosis and coexisting infertility or pelvic pain. The results of the analyses support that an association exists between elevated serum IL-6 and/or IL-8 concentrations and the occurrence of endometriosis-associated infertility. Such association was not found for endometriosis-associated pain. In spite of accumulated evidence on the association of pro-inflammatory cytokines and endometriosis, it still is not clear if and how these mediators participate in the physiopathology of endometriosis-associated infertility or pelvic pain, in part due to poor quality of the evidence established in the vast majority of interleukins and challenges in endometriosis research reproducibility. In summary, the results of the analyses support that an association exists between elevated serum IL-6 and/or IL-8 concentrations and the occurrence of endometriosis-associated infertility.

Transcriptome meta-analysis reveals differences of immune profile between eutopic endometrium from stage I-II and III-IV endometriosis independently of hormonal milieu

Eutopic endometrium appears to be crucial for endometriosis development. Despite of the evident importance, data regarding the cellular microenvironment remain unclear. Our objective was to explore the tissue microenvironment heterogeneity, transcripts, and pathways that are enriched in all phases of the menstrual cycle by analysing publicly deposited data derived from whole transcriptome microarrays of eutopic endometria of women with and without endometriosis. A meta-analysis of the transcriptome microarrays was performed using raw data available from a public database. Eligibility criteria included eutopic endometrium samples from women with endometriosis and healthy controls without any pathological condition reported the presence of an adequately reported normal menstrual phase, and samples containing both glandular and stromal components. Raw data were processed using a robust multiarray average method to provide background correction, normalisation, and summarisation. The batch effect was estimated by principal variant component analysis and removed using an empirical Bayes method. Cellular tissue heterogeneity was inferred using the xCell package. Differentially expressed genes were identified based on a 5% adjusted p value and a 2.0-fold change. Pathways were identified by functional enrichment based on the Molecular Signatures Database, a p value of < 5%, and an FDR q value of ≤ 25%. Genes that were more frequently found in pathways were identified using leading edge analysis. In a manner independent of cycle phase, the subpopulations of activated dendritic cells, CD4 T effector memory phenotype cells, eosinophils, macrophages M1, and natural killer T cells (NKT) were all higher in stage I-II endometriosis compared to those in healthy controls. The subpopulations of M2 macrophages and natural killer T cells were elevated in eutopic endometriums from women with stage III-IV endometriosis, and smooth muscle cells were always more prevalent in healthy eutopic endometriums. Among the differently expressed genes, FOS, FOSB, JUNB, and EGR1 were the most frequently mapped within the interaction networks, and this was independent of stage and cycle phase. The enriched pathways were directly related to immune surveillance, stem cell self-renewal, and epithelial mesenchymal transition. PI3K AKT mTOR, TGF signalling, and interferon alpha/gamma responses were enriched exclusively in stage III-IV endometriosis. The cellular microenvironments and immune cell profiles were different between eutopic endometriums from women with stage I-II and stage III-IV endometriosis, and these differences were independent of the hormonal milieu. Specifically, a pro-inflammatory profile was predominant in stage I-II endometriosis, and M1-M2 polarization into eutopic endometrium may be crucial for the progression of the disease. The higher prevalence of NKT cells in eutopic endometriums from women with endometriosis that was independent of cycle phase or staging suggested a sustained stress and/or damage to these eutopic endometriums. Based on this, the results of this meta-analysis are important for identifying challenges and opportunities for future research.

Analysis of IVF/ICSI-FET Outcomes in Women With Advanced Endometriosis: Influence on Ovarian Response and Oocyte Competence

Aims: To determine the impact of advanced endometriosis (EMS) on in vitro fertilization/intracytoplasmic sperm injection and frozen-thawed embryo transfer (IVF/ICSI-FET) outcomes and analyze the influencing factors. Methods: A retrospective study was conducted on sterile women with ovarian endometriomas (OMAs), including patients who underwent laparoscopic cystectomy (n = 224, 224 IVF/ICSI cycles, 205 FET cycles) and aspiration (n = 139, 139 IVF/ICSI cycles, 148 FET cycles); peritoneal EMS (n = 96, 96 IVF/ICSI cycles, 89 FET cycles); and tubal factors (n = 360, 360 IVF/ICSI cycles, 474 FET cycles). Our main outcomes included the number of MII oocytes retrieved, fertilization rate, the number of viable embryos, viable embryo rate per oocyte retrieved in oocyte retrieval cycles, and clinical pregnancy rate per transfer, live birth rate per transfer, and cumulative clinical pregnancy rate of this oocyte retrieval cycle in FET cycles. Finally, binary logistic regression analysis was performed to generate a prediction model for cumulative clinical pregnancy. Results: The results showed that significantly fewer MII oocytes retrieved and viable embryos and lower viable embryo rate and cumulative clinical pregnancy rate were observed in women with EMS compared with the control. Women with peritoneal EMS had lower fertilization rate and viable embryo rate per oocyte retrieved than patients with OMA (all p < 0.05). However, the pregnancy outcomes were not significantly different between the two phenotypes. The patients who underwent laparoscopic cystectomy had fewer MII oocytes retrieved and viable embryos compared with those with intact endometrioma(s) but no significant difference in pregnancy outcomes between the two types of OMA patients. By binary logistic regression analysis, antral follicle count (AFC) was found to be an independent factor associated with cumulative clinical pregnancy in this oocyte retrieval cycle (odds ratio = 1.054; 95% confidence interval, 1.011-1.100; p = 0.014), and the AFC prediction model of cumulative clinical pregnancy was established, with an area under the curve of 0.60. Conclusions: Our data supported that advanced EMS has negative effect on cumulative clinical pregnancy per oocyte retrieval cycle, and AFC is an independent predictor, which is mainly caused by poor ovarian response associated with OMA per se or its surgery and the damage of peritoneal EMS to oocyte maturation.

Curcumin improves growth factors expression of bovine cumulus-oocyte complexes cultured in peritoneal fluid of women with endometriosis

Background

Peritoneal fluid (PF) from infertile women with endometriosis contains inflammatory mediators that may interfere with folliculogenesis.

Objective

The aim was to evaluate the effects of curcumin on growth factors expression by evaluating Growth Differentiation Factor-9 (GDF-9), Kit Ligand (KitL), and Tumor Necrosis Factor α (TNFα) expressions in bovine cumulus-oocyte complexes (COC)s cultured with PF from infertile women with endometriosis.

Materials and Methods

In this experimental study, 21 infertile women (aged between 20 and 40 years) who refered to Dr Sutomo Hospital from January to July 2015 were enrolled. COCs were aspirated from antral follicles of bovine ovaries. PF was collected from infertile women with endometriosis undergoing laparoscopy for infertility evaluation. Curcumin, a strong anti-inflammatory turmeric, was added in Tissue Culture Medium 199 (TCM199) and PF for culture medium. Bovine COCs were cultured into three groups of the medium: 1. TCM199, 2. TCM199 + PF, and 3. TCM199 + PF + curcumin. GDF-9, KitL, and TNFα expressions were examined using immunohistochemistry technique.

Results

GDF-9 expression of bovine COCs cultured in PF with curcumin addition (2.67 ± 0.98) was found to increase compared to those cultured without curcumin (0.50 ± 0.67) (p≤ 0.001). It was similar to KitL expression of bovine COCs cultured with curcumin (2.67 ± 1.23), which increased compared to those without curcumin (0.33 ± 0.49) (p≤ 0.001). A significant difference in TNFα expression was noted between groups with or without curcumin (p≤ 0.001).

Conclusion

In the culture of PF from infertile women with endometriosis, curcumin addition improves the growth factors expression of bovine COCs. The increase of GDF-9 and KitL expressions will improve folliculogenesis.