Ethiopathogenic mechanisms of endometriosis-related infertility

Decreased expression of miR-200a and miR-223-3p in endometriosis during the secretory phase of menstrual cycle: Insights from a case-control study on molecular biomarkers and disease-related infertility

Background

Endometriosis (EM) is a condition that causes infertility with decreasing uterine receptivity. It is reported that it affects about 20-25% of all infertile women. Some genetic markers play a crucial role in pathogenesis and infertility.

Objective

This study investigates the role of miR-200a and miR-223-3p in embryo implantation and their association with EM-related infertility.

Materials and Methods

In this case-control study, 36 women who referred to the Center for Research on Reproductive Health and Infertility of Babol University of Medical Sciences and Fatemeh Al-Zahra Infertility Specialized Treatment Center in Babol, Iran between June 2022 and July 2023 were evaluated. Participants were divided into 2 EM and control groups (n = 18/each). Endometrial samples were collected from participants between 17  th and 24  th days of their menstrual cycle. Histopathological examination (hematoxylin and eosin and periodic acid schiff) was performed to confirm the secretory stage, and miR-200a and miR-223-3p expressions were analyzed by quantitative reverse transcriptase-polymerase chain reaction.

Results

Histological analysis confirmed that both groups were in the secretory stage. Additionally, miRNA expression results showed a significant decrease in the miR-200a and miR-223-3p expression levels in EM group compared to control group. The expression level of miR-223-3p and miR-200a in the eutopic endometrial tissue of women with EM was notably lower than those in the control group.

Conclusion

Our results suggest that miR-200a and miR-223-3p are involved in the EM pathogenesis, while other genes and signaling pathways are probably involved in the implantation failure.

How does chronic endometritis influence pregnancy outcomes in endometriosis associated infertility? A retrospective cohort study

BACKGROUND

Endometriosis (EMS) and chronic endometritis (CE) frequently coexist. This study aimed to examine the impact of CE on reproductive outcomes in patients with EMS.

METHODS

We enrolled 685 patients with endometriosis-associated infertility from January 2018 to December 2020. The patients were divided into CE (318) and non-CE (367) groups. A subset of 123 clinically pregnant women from the CE group and 369 from the non-CE group was selected for detailed comparison. Pregnancy and delivery data were meticulously collected from hospital records and through telephone interviews.

RESULTS

CE was diagnosed in 46.42% of EMS patients. Higher pregnancy rates were observed in patients with Endometriosis Fertility Index (EFI) scores of 7-10. EMS patients with CE had increased risks of placenta previa (13.01%), gestational hypertension (5.69%), and cesarean sections (59.34%).

CONCLUSIONS

CE, which is prevalent among EMS patients, is linked to increased risks of pregnancy complications, including placenta previa, gestational hypertension, and cesarean delivery. Although combined hysteroscopy and laparoscopy improve pregnancy rates, they demand careful management of these complications.

Correlation of Glycolysis-immune-related Genes in the Follicular Microenvironment of Endometriosis Patients with ART Outcomes

Endometriosis (EMT) -related infertility has been a challenge for clinical research. Many studies have confirmed that abnormal alterations in the immune microenvironment and glycolysis are instrumental in causing EMT-related infertility. Recently, our research team identified several key glycolysis-immune-related genes in the endometrial cells of EMT patients. This study aimed to further investigate the expression patterns of pyruvate dehydrogenase kinase 3 (PDK3), glypican-3 (GPC3), and alcohol dehydrogenase 6 (ADH6), which are related to glycolysis and immunity, in the follicular microenvironment of infertile patients with EMT using enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. According to the results, compared to the patients with tubal factor infertility, the concentrations of PDK3 and GPC3 were considerably increased in the follicular environment of EMT patients, while ADH6 expression was significantly reduced. The number of oocytes retrieved, the transferable embryo rate, and the cumulative clinical pregnancy rate of EMT patients were significantly reduced, and there was a correlation with the level of PDK3, GPC3, and ADH6 in Follicular Fluid (FF). The area under the receiver operating characteristic (ROC) curve for predicting clinical pregnancy in infertile patients with EMT for PDK3, GPC3, ADH6, and their combination was 0.732, 0.705, 0.855, and 0.879, respectively (P < 0.05). In conclusion, our research indicates that glycolysis-immune-related genes may contribute to infertility in EMT patients through immune infiltration, and disruption of mitochondrial and oocyte functions. The combined detection of PDK3, GPC3, and ADH6 in FF helps to predict clinical pregnancy outcomes in infertile patients with EMT.

A Comprehensive Review of the Efficacy and Safety of Dopamine Agonists for Women with Endometriosis-associated Infertility from Inception to July 31, 2022

Background

Current medical management of endometriosis leads to suppression of ovulation and will not be helpful for women with endometriosis who are desirous of pregnancy. Thus, drugs that can both treat endometriosis and its associated infertility are highly warranted.

Objective

Anti-angiogenic agents are potential drugs for patients with endometriosis and infertility. Among these drugs, dopamine agonist (DA) is promising since it does not interfere with ovulation, is safe, and not teratogenic. The aim of the study is to determine the efficacy and safety of DA for improving reproductive outcomes in women with endometriosis and infertility.

Methods

A qualitative narrative review was done from inception to July 31, 2022 using the appropriate MeSH terms in PubMed, Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, ClinicalTrial.gov, and World Health Organization International Clinical Trials Registry Platform. Date analysis was through qualitative analysis and synthesis of researches and their outcome measures.

Results

No studies used the core outcomes for trials evaluating treatments for infertility associated with endometriosis. All the included articles in the review supported the possible anti-angiogenic effects of DA on the vascular endothelial growth factor [VEGF] /VEGF receptor system. The use of DA does not have an effect on ovulation and menstrual cyclicity. Studies on safety profile of DA were consistent with existing data.

Conclusion

Most of studies reviewed demonstrated that DA were effective in reducing endometriotic lesions. However, further research is required to establish whether this anti-angiogenic effect can improve reproductive outcomes in women with endometriosis-associated infertility.

Loss of KLF15 impairs endometrial receptivity by inhibiting EMT in endometriosis

The impaired endometrial receptivity is a major factor contributing to infertility in patients with endometriosis (EM), but the underlying mechanism remains unclear. Our study aimed to investigate the role of Kruppel-like factor 15 (KLF15) in endometrial receptivity and its regulation in EM. We observed a significant decrease in KLF15 expression in the mid-secretory epithelial endometrial cells of EM patients compared to normal females without EM. To confirm the role of KLF15 in endometrial receptivity, we found a significantly reduced KLF15 expression and a significant decrease in embryo implantation number in the rat model via uterine horn infection with siRNA. This highlights the importance of KLF15 as a regulator receptivity. Furthermore, through ChIP-qPCR, we discovered that the progesterone receptor (PR) directly binds to KLF15 promoter regions, indicating that progesterone resistance may mediate the decrease in KLF15 expression in EM patients. Additionally, we found that the mid-secretory endometrium of EM patients exhibited impaired epithelial-mesenchymal transition (EMT). Knockdown of KLF15 upregulated E-cadherin and downregulated vimentin expression, leading to inhibited invasiveness and migration of Ishikawa cells. Overexpression KLF15 promotes EMT, invasiveness, and migration ability, and increases the attachment rate of JAR cells to Ishikawa cells. Through RNA-seq analysis, we identified TWIST2 as a downstream gene of KLF15. We confirmed that KLF15 directly binds to the promoter region of TWIST2 via ChIP-qPCR, promoting epithelial cell EMT during the establishment of endometrial receptivity. Our study reveals the involvement of KLF15 in the regulation of endometrial receptivity and its downstream effects on EMT. These findings provide valuable insights into potential therapeutic approaches for treating non-receptive endometrium in patients with EM.

Downregulation of lncRNA LINC01465 predicts ovarian endometriosis and its prognosis

The well-known impact of ovarian endometriosis on female quality of life and the established role of lncRNA LINC01465 in ovarian cancer pathogenesis have been extensively documented; however, the relationship between LINC01465 and ovarian endometriosis is still not clear. This study seeks to explore the potential involvement of LINC01465 in the disease. The study analyzed a sample of 80 endometriosis patients and 80 healthy women. The expression of LINC01465 was measured in ectopic and eutopic endometrial tissues through RT-qPCR. The diagnostic potential of serum LINC01465 levels was evaluated using ROC curve analysis, and the patients were followed up for 3 years after treatment to monitor recurrence. The results revealed that the expression of LINC01465 was significantly lower in ectopic endometrial tissues in comparison to paired eutopic tissues for most of the patients. No correlation was found between the patient's age or lifestyle and serum LINC01465 levels. After treatment, the serum LINC01465 level increased, and patients who experienced recurrence had significantly lower levels compared to those who did not. In conclusion, the study findings suggest that the downregulation of LINC01465 plays a role in the pathogenesis of ovarian endometriosis and may serve as a diagnostic and prognostic biomarker for the disease.

Primer on Female Infertility for the Reproductive Urologist

This review is intended to serve as an aid in decision-making and patient counseling for the reproductive urologist when female factor infertility is found concurrently with male factor infertility. This review pairs the pathophysiology of female infertility with its implications for the treatment of male infertility, which most commonly includes ovulatory disorders, tubal abnormalities, and uterine abnormalities. By gaining a deeper understanding of these factors, reproductive urologists can employ a tailored approach to managing male factor infertility, taking into account the female partner's specific medical history.

Prophylaxis of decidual CD68+/CD163+ macrophage disbalance in extracorporeal fertilized women

The demographic crisis that prevailed in Ukraine in recent years, the state of war as a result of the aggression of the Russian Federation, reproductive losses among women of childbearing age are one of the most urgent problems in modern obstetrics and gynecology. One of the most effective methods of correcting impaired reproductive function is in vitro fertilization.

The purpose of this work

is to develop a pharmacological complex for the prevention of imbalance of CD68+/CD163+ decidual macrophages in vitro fertilized women.

Materials and methods

105 pregnant women who were divided into 3 groups took part in the study. The first group included 20 women whose pregnancy occurred and is proceeding physiologically. The second group consisted of 85 women who became pregnant as a result of in vitro fertilization, including 37 pregnant women who refused prophylactic correction of the threat of premature birth, and 48 pregnant women who received prophylactic correction of the threat of premature birth: complex prescription of vitamin D3 2000 IU orally 2 times a day, micronized progesterone 200 mg 2 times a day and l-arginine aspartate 1000 mg 4 times a day, starting from 18 to 20 weeks of pregnancy.

Results

In women who refused prophylactic correction of the threat of premature birth, a local increase in the activity of inducible NO-synthase and concentration of tumor necrosis factor-α, and a decrease in the activity of arginase and in the level of interleukin-10 were observed in the cervical mucus. They have a lower expression of CD163+ on placental decidual macrophages and an increased expression of CD68+, which indicates a shift in the polarization of macrophages from an anti-inflammatory to a pro-inflammatory phenotype. The use of prophylactic treatment brings the studied parameters closer to the results of women in whom pregnancy occurred physiologically.

Conclusions

In women who became pregnant as a result of in vitro fertilization, at 28-30 weeks of pregnancy, changes specific for pro-inflammatory phenotype of decidual macrophages were observed. Complex administration of vitamin D3, micronized progesterone and l-arginine aspartate lead to restoration of anti-inflammatory phenotype of decidual macrophages.

Icariin, A Novel Promising Complementary Therapeutic Strategy in the Management of Female Infertility: A Literature Review:

The prevalence of pre-menopausal female infertility is increasing considerably due to various causes such as environmental pollutants, increased administration of chemotherapeutics and radiation exposure, microbial infections, and genetic/epigenetic alterations. However, the current therapeutical strategies remain unfavorite as the disadvantages are strongly challenging. Icariin (ICI) is a phytoestrogen that exerts some promising properties in order to alleviate female infertility. Therefore, the current literature review aimed to evaluate the conducted studies regarding the beneficial impacts of ICI on the female reproductive system and female fecundity. The findings of the present study revealed that ICI is able to modulate the levels of reproductive hormones as it causes a significant decrement in the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) while increasing the levels of estrogen and progesterone. Furthermore, the administration of ICI results in a dramatic alteration in the expression of sex steroids’ receptors, particularly in female reproductive tissues. In addition, preserving ovarian follicular reserve, improving the ovarian and uterine histoarchitecture, elongating the estrous cycle duration, and eventually advancing the female fecundity are other major effects of ICI on the female reproductive system. Despite these desired beneficial properties, the current knowledge appears to be insufficient, hence further investigations, particularly on humans, are encouraged. To the best of our knowledge, this review provides a comprehensive information regarding the beneficial effects of Icariin on female infertility for the firs time.

A comparative study between Dydrogesterone alone and combined with Non-Steroidal Anti-Inflammatory Drugs in the treatment of Mild Endometriosis

Objective

To evaluate the clinical efficacy of dydrogesterone combined with non-steroidal anti-inflammatory drugs(NSAIDs) in the treatment of patients with mild endometriosis.

Methods

This was a clinical comparative study. Eighty patients with mild endometriosis were recruited at Affiliated Hospital of Hebei University, randomly divided experimental group (n=40) and control group (n=40) from March 2022 to March 2023. Both groups started treatment with dydrogesterone on the 5th day of menstruation. Patients in the control group were treated with dydrogesterone monotherapy, while those in the experimental group were treated with mefenamic acid the basis of the therapy of the control group. The clinical efficacy, differences in the levels of humoral immune indexes, the levels of inflammatory factor and the incidence of adverse drug reactions of the two groups was compared and analyzed.

Results

The efficacy of the experimental group was significantly higher than the control group, with a statistically significant difference(P=0.02). The levels of C3 and C4 in the experimental group after treatment were significantly lower than those in the control group, with a statistically significant difference(P=0.00). After treatment, TNF-a, CRP, IL-6 and other indexes in the experimental group were significantly lower than those in the control group, with statistically significant differences(P=0.00). The incidence of adverse reactions after treatment had no statistically significant difference(P=0.45).

Conclusion

Dydrogesterone combined with non-steroidal anti-inflammatory drugs is a safe and effective treatment for patients with endometriosis. It can improve various obvious curative effects, such as marked relief of pain symptoms, reduction of complement and inflammatory factor levels without a significant increase in adverse reactions.

Phthalate exposure and risk of ovarian dysfunction in endometriosis: human and animal data

Objective: We aimed to explore the correlations between and possible mechanisms of common environmental endocrine disruptors, phthalates, and ovarian dysfunction in endometriosis. Methods: Subjects were included in the case group (n = 107) who were diagnosed with endometriosis by postoperative pathology in Fujian Maternal and Child Hospital from February 2018 to February 2021, and the women who were excluded from endometriosis by surgery were as the control group (n = 70). The demographic information of the subjects were evaluated by questionnaire, and the clinical characteristics were evaluated by medical records and 3-year follow-up results. Gas chromatography‒mass spectrometry was used to quantify 10 metabolites of phthalates, including dimethyl ortho-phthalate (DMP), mono-n-methyl phthalate (MMP), dioctyl ortho-phthalate (DEP), mono-ethyl phthalate (MEP), di-n-butyl ortho-phthalate (DBP), mono-butyl phthalate (MBP), benzylbutyl phthalate (BBzP), mono-benzyl; phthalate (MBzP), diethylhexyl phthalate (DEHP) and mono-ethylhexyl phthalate (MEHP), in the urine samples of the subjects. Furthermore, a total of 54 SD rats were exposed to DEHP 0, 5, 50, 100, 250, 500, 1,000, 2000, and 3,000 mg/kg/day for 2 weeks. The SD rats' body weight, oestrus cycle changes, and serum anti-mullerian hormone (AMH) levels were evaluated. After sacrifice, the mass index of the rat uterus and bilateral ovaries were calculated. Finally, bioinformatics analysis of rat ovarian tissues was performed to explore the possible mechanism. SPSS 24.0 (IBM, United States) was used for data analysis. p-value <0.05 was considered statistically significant. Results: The human urinary levels of DMP (p < 0.001), MMP (p = 0.001), DEP (p = 0.003), MEP (p = 0.002), DBP (p = 0.041), MBP (p < 0.001), BBzP (p = 0.009), DEHP (p < 0.001), and MEHP (p < 0.001) were significantly higher in women with endometriosis than in controls. Notably, DEHP was a significant risk factor for endometriosis (OR: 11.0, 95% CI: 5.4-22.6). The area under the ROC curve increased when multiple phthalates were diagnosed jointly, reaching 0.974 as the highest value, which was helpful for the diagnosis of endometriosis. In vivo experiments showed that after DEHP exposure in rats, the mass index of the ovary and uterus decreased in a dose-dependent manner; the oestrus cycle of SD rats was irregularly prolonged and disordered; and the serum AMH level was negatively correlated with the DEHP exposure dose (Rho = -0.8, p < 0.001). Bioinformatics analysis of rat ovarian tissues showed that seven genes involved in the steroid biosynthesis pathway were upregulated and may play a negative role in ovarian function. Conclusion: Exposure to phthalates, especially DEHP, is associated with the occurrence of endometriosis and affects women's reproductive prognosis and ovarian function. The steroid biosynthesis pathway may be related to ovarian dysfunction. The detection of phthalate in urine may become a new biological target for the diagnosis of endometriosis.

Adverse Pregnancy Outcomes Associated with Endometriosis and Its Influencing Factors

Aim

To investigate the adverse pregnancy outcomes associated with endometriosis and its influencing factors.

Methods

A total of 188 endometriosis patients who gave birth at our hospital between June 2018 and January 2021 were screened for eligibility and included in the research group, while a control group of 188 nonendometriosis women who delivered at our hospital during the same period were also included as healthy controls. Pregnancy outcomes were the key outcome measure, and the relationship between endometriosis and unfavorable pregnancy outcomes, as well as the influencing factors, were explored.

Results

There was no significant difference in the risk of adverse pregnancy events such as miscarriage, ectopic pregnancy, termination of pregnancy, and fetal death between the two groups (P > 0.05). The differences in hypertensive disorder in pregnancy, gestational diabetes, placental abruption, fetal growth restriction, and luteal support between the two groups also failed to reach the statistical standard (P > 0.05). The two groups significantly differed in terms of cesarean delivery, preterm delivery, and placenta previa (1.92 (95% CI 1.33-2.85), 2.43 (95% CI 1.05-5.58), and 4.51 (95% CI 1.23-16.50)) (P < 0.05).

Conclusion

Endometriosis is an influential factor in adverse pregnancy outcomes and results in a high risk of preterm delivery, placenta previa, and cesarean delivery in patients. Mutual interactions exist among adverse pregnancy outcomes and thus require appropriate management.

Conventional IVF performs similarly in women with and without endometriosis

PURPOSE

A reduced oocyte competence has been claimed as one of the factors underlying infertility in women with endometriosis. This idea has justified the hypothesis that intracytoplasmic sperm injection (ICSI), rather than conventional IVF (c-IVF), may overcome oocyte impairment and ensure better assisted reproduction technology (ART) outcomes; however, data from the literature are controversial. Thus, the aim of this study was to compare ART success rates following (c-IVF) between women with and without endometriosis in the presence of normozoospermic partners.

METHODS

This is a retrospective, matched case-control study of 314 patients who underwent c-IVF cycles between January 2014 and December 2020. Women with endometriosis were matched in a 1:1 ratio with patients undergoing ART for other indications, considering age (± 6 months), number of oocytes retrieved (± 1), and study period. The main outcome measures included total fertilization failure, fertilization rate, embryo quality, cumulative clinical pregnancy, and live birth rates.

RESULTS

The fertilization rate and the proportion of women with total fertilization failure did not differ between women with and without endometriosis. Similarly, all other embryological variables did not also differ, except for the number of top-quality cleavage stage embryos which was higher in the endometriosis group. Cumulative clinical pregnancy and live birth rates were similar between women with and without endometriosis.

CONCLUSION

A diagnosis of endometriosis does not negatively affect the performance of c-IVF; thus, c-IVF can be efficiently used in women affected, unless a male factor is also involved. This issue holds clinical relevance to help operators on their insemination technique decision-making.

Clinical effects of laparoscopic surgery for the treatment of endometriosis and endometriosis-fertility: A retrospective study of 226 cases

Introduction

To determine the clinical effects of laparoscopic surgery (LS) in the treatment of endometriosis and endometriosis-fertility.

Methods

Two hundred twenty-six patients with endometriosis who underwent LS (LS group, n = 176) or laparotomy (LT group, n = 50) at the Third Hospital of Shijiazhuang City from June 2011 to June 2013 were included in this study, and their clinical outcomes for endometriosis and infertility were compared. All patients were followed up for 1 year after surgery to determine postoperative pregnancies in patients with endometriosis.

Results

The operative times between the LS and LT groups were not significantly different (P > 0.05); however, the length of stay in the hospital and blood loss in the LS group were significantly different from the LT group (P < 0.05). The incidence of postoperative symptoms were lower in the LS group than the LT group (P < 0.05). The postoperative pregnancy rates in the two groups were significantly different, including the infertility patients (P < 0.05).

Conclusions

Compared with LT, LS significantly reduced pain and improved the quality of life in women with endometriosis. These results can provide a reference for the clinical treatment of endometriosis.

The presence of clear cell glands around the ovarian endometrioid cyst has an association with clear cell carcinoma

We found some clear cell glands appeared in the endometrioid cysts (ECs) of the ovary (EC-CCG). To explore the clinicopathological features, molecular biological changes, and prognosis in EC-CCG and analyze the association with ovarian clear cell borderline tumors (CCBT) and clear cell carcinoma (CCC). We retrospectively examined 35 cases of EC-CCG, compared them to 13 cases of clear cell cystadenomas, 14 cases of CCBT, and 49 cases of CCC. We analyzed the differences in clinicopathological features and prognosis between the four groups. Data on clinicopathology and survival were gathered. Immunohistochemistry (IHC) was performed in all cases, and we analyzed the molecular changes of 2 cases of EC-CCG and 1 case of CCC by whole-exome sequencing (WES). EC-CCG shared some common clinicopathological features with CCBT: they occurred before menopause, had an elevated serum CA125 level in some cases, had an ovarian cystic mass on B-ultrasound, and had a risk of recurrence. Microscopically, both diseases were based on typical EC, and clear cell glands in the EC cyst wall were seen in varying numbers. Some cases of EC-CCG had IHC results similar to those of CCBT and CCC, with positive expression of HNF1β and NapsinA; decreased expression of ER, PR, and ARID1A; and increased expression of Ki67 (> 5%). WES results revealed that EC-CCG had mutations in TP53BP1, ZNF462, FN1, and FTL (which was also mutated in CCC). In summary, we found that clear cell glands appearing around EC in the ovary have an association with CCC.

Expression of Fucosyltransferase 4 (FUT4) mRNA Is Increased in Endometrium from Women with Endometriosis

Endometriosis is a common gynecological disorder defined as the presence of endometrial-like tissue (glands and stroma) outside the uterus. The etiopathogenesis of endometriosis is still poorly recognized. It is speculated that stage-specific embryonic antigen 1 (SSEA-1)-positive stem-like glandular epithelial cells may contribute to the development of the disease. The synthesis of SSEA-1 is mediated by fucosyltransferase 4 encoded by the FUT4 gene. Therefore, this study aimed to evaluate the specific expression of FUT4 mRNA in biopsies of the endometrium from women with and without endometriosis. FUT4 mRNA levels were examined in 49 women with laparoscopically confirmed endometriosis and 28 controls by means of quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The expression of FUT4 mRNA was significantly increased in the endometrium of patients with endometriosis when compared to the controls (p < 0.0001). Expression of FUT4 mRNA in the endometrium was correlated with the severity of endometriosis (rs = 0.5579, p < 0.0001); however, there were no differences in endometrial FUT4 mRNA expression when comparing endometriotic lesions from various locations. The discriminatory ability of FUT4 mRNA expression was evaluated by receiver-operating characteristics (ROC), which showed high statistical significance (AUC = 0.90, p < 0.0001), thus indicating that an increased level of endometrial FUT4 mRNA may serve as a specific marker for endometriosis.

Mechanism of Thunberg Fritillaria in treating endometriosis based on network pharmacology and the effect of Peiminine on the MEK/ERK pathway

OBJECTIVE

To explore the mechanism of Thunberg Fritillaria in treating endometriosis (EMs) based on network pharmacology and the effect of Peiminine on the MEK/ERK pathway.

METHODS

We applied Chinese medicine system pharmacology analysis platform (TCMSP) database and literature search to screen the main chemical components of Fritillaria thunbergii Miq and created a Vanny map from the databases of TCMSP, GENECARDS, Online Mendelian Inheritance in Man (OMIM), and some others. The STRING database was used to construct the protein interaction network of Fritillaria thunbergii Miq and EMs. The overlapping targets and enriched pathways were discovered using the cells of the innate immune annotation database (DAVID) and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. To test the mechanism of Peiminine, the active ingredients of Fritillaria thunbergii, in the therapy of EMs, we designed cell assays and animal research. EMs mouse models were treated with several therapies, including fibrosis inhibitor in Peiminine by utilizing Hematoxylin-eosin staining (HE staining), MASSON staining, Immunohistochemistry, Immunofluorescence, quantitative real-time PCR (qRT-PCR) experiment, and Western blotting test. We evaluated the anti-endometriotic effects of Peiminine using 12Z human endometriotic cells. Cell Counting Kit 8 was used to assess the vitality of 12z cells (CCK8). We evaluated the migration ability of 12z cells by cell scratch test.

RESULTS

The effective active ingredients of Fritillaria thunbergii Miq in the treatment of EMs are Pelargonidin, Beta-sitosterol syringaresinol, Peimisine Pelargonidin-3, 5-diglucoside Ziebeimine Zhebeiresinol Verticine Solatubin OSI-2040 Chaksine Peiminine Peiminoside Peiminoside_qt, and 6-Methoxyl-2-acetyl-3-methyl-1, 4-naphthoquinone-8-O-beta-D-glucopyranoside. The critical targets for Fritillaria thunbergii Miq treating EMs are NOS2/PTGS1/AR/PPARG/PTGS2/NCOA2/RXRA/PGR/NR3C1/NCOA1/SLC6A4/OPRM1/BCL2 and ESR1. The results of GO function and KEGG enrichment analysis showed that the role pathway was estrogen-related signaling and thyroid hormone-related signaling. The expression of E-cadherin was decreased in EMs while MEK1/2, P-ERK, N-cadherin and vimentin were all increased in MASSON, immunofluorescence, Real-time PCR and Western blotting. In epithelial 12Z cells, high concentrations of Peiminine can block cell activity and migration, which is directly related to blocking cell fibrosis.

CONCLUSION

Overall, this study partially verified the network pharmacological prediction that Peiminine regulates the MAPK pathway in inhibiting 12Z cell proliferation and migration, and finally protects against EMs.

Mast Cell Activation Syndrome in COVID-19 and Female Reproductive Function: Theoretical Background vs. Accumulating Clinical Evidence

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, can affect almost all systems and organs of the human body, including those responsible for reproductive function in women. The multisystem inflammatory response in COVID-19 shows many analogies with mast cell activation syndrome (MCAS), and MCAS may be an important component in the course of COVID-19. Of note, the female sex hormones estradiol (E2) and progesterone (P4) significantly influence mast cell (MC) behavior. This review presents the importance of MCs and the mediators from their granules in the female reproductive system, including pregnancy, and discusses the mechanism of potential disorders related to MCAS. Then, the available data on COVID-19 in the context of hormonal disorders, the course of endometriosis, female fertility, and the course of pregnancy were compiled to verify intuitively predicted threats. Surprisingly, although COVID-19 hyperinflammation and post-COVID-19 illness may be rooted in MCAS, the available clinical data do not provide grounds for treating this mechanism as significantly increasing the risk of abnormal female reproductive function, including pregnancy. Further studies in the context of post COVID-19 condition (long COVID), where inflammation and a procoagulative state resemble many aspects of MCAS, are needed.

Endometriosis and Subfertility: A Literature Review

Introduction: Endometriosis is a condition that mainly concerns women of reproductive age, which causes several problems, including subfertility. The phenotypic presentation of endometriosis is defined by a complex interplay between genetic profile, immunological and mechanical factors. In this literature review we examine the causality between endometriosis and subfertility, outlining possible mechanisms involved in the pathogenesis. Aim: The purpose of this study was to conduct a literature review in order to identify the correlation between endometriosis and subfertility through possible mechanisms involved in the pathogenesis of endometriosis-associated subfertility and treatment. Methods:A search in Medline/PubMed was done, using the terms "endometriosis" and "subfertility", to identify the most relevant studies that were published during the last six years. Results:Pathogenesis of endometriosis-associated subfertility is not clear yet, although some data indicate that there are several factors that could affect a patient's fertility. Involved mechanisms include mechanical obstruction such as ovarian tubal dysfunction and the abnormal peritoneal microenvironment, genetic, and epigenetic mechanisms, and immunological traits. It is fundamental to better understand these mechanisms in order to improve the therapeutic approach. Conclusions:The clinical management of endometiosis-related subfertility has to be improved. It is important to consider a change in the classification of endometriosis and, more importantly, an effort to avoid surgical procedures. There is a crucial need for effective protocols and novel targets for specific diagnosis and treatment. Consequently, the importance of understanding pathogenesis and genetic mechanisms is underlined. Future researchers should focus on novel non-invasive treatment methods that target specific pathogenic pathways.

Altered gene expression of VEGF, IGFs and H19 lncRNA and epigenetic profile of H19-DMR region in endometrial tissues of women with endometriosis

Background

Endometriosis, as chronic estrogen-dependent disease, is defined by the presence of endometrial-like tissue outside the uterus. Proliferation of endometrial tissue and neoangiogenesis are critical factors in development of endometriosis. Hence, vascular endothelial growth factor (VEGF) as well as insulin‐like growth factor 1 and 2 (IGF1, 2) may be involved as inducers of cellular proliferation or neoangiogenesis. Imprinted long noncoding RNA H19 (lncRNA H19) has been suggested to be involved in pathogenesis of endometriosis via regulation of cellular proliferation and differentiation. Epigenetic aberrations appear to play an important role in its pathogenesis. The present study was designed to elucidate VEGF, IGF1, IGF2 and H19 lncRNA genes expression and epigenetic alterations of differentially methylated region (DMR) of H19 (H19-DMR) regulatory region in endometrial tissues of patients with endometriosis, in comparison with control women.

Methods

In this case–control study, 24 women with and without endometriosis were studied for the relative expression of VEGF, IGF1, IGF2 and H19 lncRNA genes using real-time polymerase chain reaction (PCR) technique. Occupancy of the MeCP2 on DMR region of H19 gene was assessed using chromatin immunoprecipitation (ChIP), followed by real-time PCR.

Results

Genes expression profile of H19, IGF1 and IGF2 was decreased in eutopic and ectopic endometrial tissues of endometriosis group, compared to the control tissues. Decreased expression of H19 in ectopic samples was significant in comparison with the controls (P < 0.05). Gene expression of VEGF was increased in eutopic tissues of endometriosis group, compared to control group. Whereas its expression level was lower in ectopic lesions versus eutopic and control endometrial samples. ChIP analysis revealed significant and nearly significant hypomethylation of H19-DMR region II in eutopic and ectopic samples, compared to the control group respectively. This epigenetic change was aligned with expression of IGF2. While methylation of H19-DMR region I was not significantly different between the eutopic, ectopic and control endometrial samples.

Conclusion

These data showed that VEGF, IGF1, IGF2 and H19 lncRNA genes expression and epigenetic alterations of H19 lncRNA have dynamic role in the pathogenesis of endometriosis, specifically in the way that hypomethylation of H19-DMR region II can be involved in IGF2 dysregulation in endometriosis.

Efficacy of Laparoscopic Surgery Combined With Leuprorelin in the Treatment of Endometriosis Associated With Infertility and Analysis of Influencing Factors for Recurrence

Objective

To explore the curative effect of laparoscopic surgery combined with leuprorelin in the treatment of endometriosis with infertility and the related factors of recurrence after treatment.

Methods

A total of 158 patients with endometriosis and infertility were selected in our hospital from January 2019 to June 2020. Patients were randomly divided into the control group and the observation group, with 79 patients in each group. Patients in the control group was treated by laparoscopy surgery combined with dydrogesterone, while those in the observation group was treated with laparoscopic surgery combined with leuprorelin. The hormone levels, recurrence rate, pregnancy rate and adverse reaction of the two groups were compared. Combined with clinical and pathological information, the related factors of postoperative recurrence were analyzed.

Results

After treatment, the levels of luteinizing hormone, follicle-stimulating hormone and estradiol in the observation group were lower than those in the control group (P &lt; 0.05). The recurrence rate at 12 months after operation in the observation group was lower than that in the control group, and the pregnancy rate was higher than that in the control group (P &lt; 0.05). However, there was no significant difference in the incidence of adverse reactions between the two groups (P &gt; 0.05). Preoperative dysmenorrhea was an independent risk factor for postoperative recurrence in patients with endometriosis, and postoperative pregnancy was a protective factor for postoperative recurrence in patients with endometriosis (P &lt; 0.05).

Conclusion

Laparoscopy combined with leuprorelin in the treatment of endometriosis with infertility can improve hormone levels, increase the pregnancy rate and reduce the recurrence rate. Preoperative dysmenorrhea is an independent risk factor for postoperative recurrence, which should be quantified and included in the recurrence risk prediction model. Postoperative pregnancy can reduce the recurrence rate after operation, and patients with fertility requirements should be encouraged to make activ preparations for postoperative pregnancy.

Immunonutrients involved in the regulation of the inflammatory and oxidative processes: implication for gamete competence

Purpose

The purpose of this umbrella review is to bring together the most recent reviews concerning the role of immunonutrients for male and female infertility.

Methods

Regarding immunonutrients and fertility, the authors have analyzed reviews, systematic reviews, and meta-analyses published between 2011 and June 2021. All reviews on animal or in vitro studies were excluded. Relevant keywords to term micronutrients were analyzed alone or in association with other terms such as “gamete competence,” “male OR female fertility,” “male OR female infertility,” “fertile, “folliculogenesis,” “spermatogenesis,” “immunomodulation,” “immune system,” “oxidative stress.”

Results

The primary research has included 108 results, and after screening by title, abstract. and not topic-related, 41 studies have been included by full texts. The results show the molecular mechanisms and the immunonutrients related impact on gamete formation, development. and competence. In particular, this review focused on arginine, glutamine, vitamin C, vitamin D, vitamin E, omega-3, selenium, and zinc.

Conclusions

Inflammation and oxidative stress significantly impact human reproduction. For this reason, immunonutrients may play an important role in the treatment of infertile patients. However, due to the lack of consistent clinical trials, their application is limited. Therefore, the development of clinical trials is necessary to define the correct supplementation, in case of deficiency.

The Mechanism Exploration of Follicular Fluids on Granulose Cell Apoptosis in Endometriosis-Associated Infertility

Objective

To explore the mechanisms of follicular fluids (FFs) on granulose cell (GC) apoptosis in endometriosis-associated infertility.

Materials and Methods

60 infertile women were enrolled. The FFs from 30 endometriosis-associated infertility (EI) patients were collected and processed by ELISA hormone assay and proteomic profiling. The ovary GCs collected from 30 tubal-associated infertility (TI) patients were cultured in follicular fluids of endometriosis-associated infertility patients (EI-FFs), and the apoptosis mechanisms were explored by flow cytometry assay, real-time PCR, Western blotting, and protein-protein interaction (PPI) network analysis.

Results

Our results showed that the expression of 22 specific proteins was significantly different in the FFs from EI and TI patients, and the level of testosterone and anti-Müllerian hormone was not obviously different between the two groups. EI-FFs could accelerate the apoptosis process of granulose cells of tubal-associated infertility patients (TI-GCs) by regulating the expression of 5 apoptosis-related proteins including BCL2, BAX, CASP3, CASP9, and TP53. The correlation of these 22 specific proteins and 5 apoptosis-related proteins was analyzed by PPI, and 5 protein biomarkers (INS, CXCL10, ICAM1, WIF1, and TNFRSF13C) and 5 signaling pathways (cytokine-cytokine receptor interaction, apoptosis, regulation of actin cytoskeleton, MAPK, and p53 signaling pathway) were predicted.

Conclusion

This research clarified the effect and explored the mechanisms of EI-FFs on the apoptosis of TI-GCs and indicated the protein biomarkers and signaling pathways for further study.

Impact of endometriosis on oocyte morphology in IVF-ICSI: retrospective study of a cohort of more than 6000 mature oocytes

BACKGROUND

Infertility associated with endometriosis can be explained by several non-exclusive mechanisms. The oocyte plays a crucial role in determining embryonic competence and this is particularly relevant for in vitro fertilization (IVF) outcomes. According to some authors, the morphology of oocytes could also be a non-invasive marker of oocyte quality. The aim of this study was to evaluate the relationship between endometriosis and oocyte morphology after controlled ovarian stimulation for intracytoplasmic sperm injection (ICSI) on a large oocyte cohort.

METHODS

Single-center comparative retrospective study in the academic In Vitro Fertilization (IVF) unit of the Lille University Hospital. A total of 596 women treated for IVF-ICSI with ejaculated spermatozoa for sperm alterations were included. They were classified as endometriosis (n = 175) or control groups (n = 401). The morphological evaluation of 2,016 mature oocytes from 348 cycles of patients with endometriosis was compared with that of 4,073 mature oocytes from 576 control cycles. The main outcome measures were Average Oocyte Quality Index (AOQI) and metaphase II oocyte morphological scoring system (MOMS). Comparison of groups was carried out by a mixed linear model and by a generalized estimation equation model with a "patient" random effect to consider that a patient might have several attempts.

RESULTS

No difference in AOQI and MOMS scores was found between endometriosis and control women (adjusted p = 0.084 and 0.053, respectively). In case of endometriosis, there were significantly fewer metaphase II oocytes retrieved, embryos obtained, grade 1 embryos and number of cumulative clinical pregnancies compared to controls. In the endometriosis group, endometriosis surgery was associated with a reduced number of mature oocytes retrieved, and the presence of endometrioma(s) was associated with some abnormal oocyte shapes. Nevertheless, no difference concerning the AOQI and MOMS scores was found in these subgroups.

CONCLUSION

Endometriosis does not have a negative impact on oocytes' morphology in IVF-ICSI.

TRIAL REGISTRATION

On December 16, 2019, the Institutional Review Board of the Lille University Hospital gave unrestricted approval for the anonymous use of all patients' clinical, hormonal and ultrasound records (reference DEC20150715-0002).

The Role of Peritoneal Macrophages in Endometriosis

Endometriosis is an estrogen-dependent gynecological disorder, defined as the growth of endometrial stromal cells and glands at extrauterine sites. Endometriotic lesions are more frequently located into the abdominal cavity, although they can also be implanted in distant places. Among its etiological factors, the presence of immune dysregulation occupies a prominent place, pointing out the beneficial and harmful outcomes of macrophages in the pathogenesis of this disease. Macrophages are tissue-resident cells that connect innate and adaptive immunity, playing a key role in maintaining local homeostasis in healthy conditions and being critical in the development and sustainment of many inflammatory diseases. Macrophages accumulate in the peritoneal cavity of women with endometriosis, but their ability to clear migrated endometrial fragments seems to be inefficient. Hence, the characteristics of the peritoneal immune system in endometriosis must be further studied to facilitate the search for new diagnostic and therapeutic tools. In this review, we summarize recent relevant advances obtained in both mouse, as the main animal model used to study endometriosis, and human, focusing on peritoneal macrophages obtained from endometriotic patients and healthy donors, under the perspective of its future clinical translation to the role that these cells play on this pathology.

Genetic and Epidemiological Similarities, and Differences Between Postoperative Intraperitoneal Adhesion Development and Other Benign Fibro-proliferative Disorders

Intraperitoneal adhesions complicate over half of abdominal-pelvic surgeries with immediate, short, and long-term sequelae of major healthcare concern. The pathogenesis of adhesion development is similar to the pathogenesis of wound healing in all tissues, which if unchecked result in production of fibrotic conditions. Given the similarities, we explore the published literature to highlight the similarities in the pathogenesis of intra-abdominal adhesion development (IPAD) and other fibrotic diseases such as keloids, endometriosis, uterine fibroids, bronchopulmonary dysplasia, and pulmonary, intraperitoneal, and retroperitoneal fibrosis. Following a literature search using PubMed database for all relevant English language articles up to November 2020, we reviewed relevant articles addressing the genetic and epidemiological similarities and differences in the pathogenesis and pathobiology of fibrotic diseases. We found genetic and epidemiological similarities and differences between the pathobiology of postoperative IPAD and other diseases that involve altered fibroblast-derived cells. We also found several genes and single nucleotide polymorphisms that are up- or downregulated and whose products directly or indirectly increase the propensity for postoperative adhesion development and other fibrotic diseases. An understanding of the similarities in pathophysiology of adhesion development and other fibrotic diseases contributes to a greater understanding of IPAD and these disease processes. At a very fundamental level, blocking changes in the expression or function of genes necessary for the transformation of normal to altered fibroblasts may curtail adhesion formation and other fibrotic disease since this is a prerequisite for their development. Similarly, applying measures to induce apoptosis of altered fibroblast may do the same; however, apoptosis should be at a desired level to simultaneously ameliorate development of fibrotic diseases while allowing for normal healing. Scientists may use such information to develop pharmacologic interventions for those most at risk for developing these fibrotic conditions.

Endometriotic Peritoneal Fluid Stimulates Recruitment of CD4+CD25highFOXP3+ Treg Cells

Endometriosis is a common gynecological disorder characterized by the presence of endometrial-like tissue outside the uterus. The disease is associated with disturbed local and systemic immunity. It has been reported that the proportion of CD4⁺CD25^highFOXP3⁺ Treg cells may be significantly increased in the peritoneal fluid of patients with endometriosis. Therefore, the aim of our study was to investigate whether the proportions of Treg cells in the peritoneal cavity of patients with endometriosis are related to the chemotactic and stimulatory activity of the local peritoneal milieu. The peritoneal fluid was collected from 13 women with ovarian endometriosis and 12 control women without the disease. T cell populations were analyzed by flow cytometry, cytokines and chemokines were evaluated using the cytometric bead kit, and cell chemotaxis was studied by cell migration assay. We confirmed that the proportions of Treg cells are increased in the peritoneal fluid of women with endometriosis as compared to the control women. Endometriosis was also associated with elevated concentrations of IL-6, IL-10, and TGF-β1/2 as well as CCL20, CXCL8, CXCL9, and CXCL10. We did not reveal any changes in the proportion of peritoneal Th17 cells and concentrations of IL-17A. Peritoneal Treg cells positively correlated with concentrations of TGF-β, IL-10, and CCL20. Endometriotic peritoneal fluid stimulated chemotaxis of both CD4⁺ and Treg cells. This chemotactic activity positively correlated with concentrations of CCL20. CCL20 stimulated the migration of Treg cells, and the chemotactic activity of the endometriotic peritoneal fluid was inhibited by neutralizing anti-CCL20 antibodies. These results imply that increased proportions of the peritoneal Treg cells in women with endometriosis may result from attraction and activation by local chemokines and cytokines, especially CCL20 and TGF-β. Since Treg cells contribute to the immunopathogenesis of endometriosis, their chemotaxis and activation may be considered as a target for therapeutic intervention.

Network Pharmacology-Based Prediction of Bioactive Compounds and Potential Targets of Wenjing Decoction for Treatment of Endometriosis

Endometriosis is a chronic estrogen-dependent inflammatory disorder that negatively affects the quality of life in women. The Wenjing decoction (WJD) is a traditional Chinese medicine that has been shown to have a therapeutic effect on endometriosis. Our study systematically explored the mechanism of WJD against endometriosis using a network pharmacology approach. Potentially bioactive compounds of WJD and their possible targets were retrieved from the Traditional Chinese Medicine System Pharmacology Database and Analysis Platform. The protein-protein interaction network and herbs-compounds-genes multinetwork were constructed using Cytoscape for visualization. Subsequently, the signaling pathways of common targets were retrieved from the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and molecular docking was performed using PyRx software. In total, 48 common targets were screened, such as IL6 and ESR1, which were related to inflammation and the endocrine system. The top five bioactive compounds were quercetin, kaempferol, wogonin, beta-sitosterol, and stigmasterol. KEGG enrichment analysis revealed 65 pathways containing inflammatory- and endocrine-related signaling pathways, such as the "TNF signaling pathway" and the "estrogen signaling pathway." Taken together, the results of our network pharmacology analysis predicted that certain active ingredients of WJD might treat endometriosis by regulating inflammation and/or endocrine, which provided references for further understanding and exploration of WJD on endometriosis.

Knockdown of lncRNA H19 suppresses endometriosis in vivo

The long noncoding RNA (lncRNA) H19 is involved in the pathogenesis of endometriosis by modulating the proliferation and invasion of ectopic endometrial cells in vitro, but related in vivo studies are rare. This study aimed to investigate the role of lncRNA H19 in a nude mouse model of endometriosis. Ectopic endometrial stromal cells (ecESCs) were isolated from ectopic endometrium of patients with endometriosis and infected with lentiviruses expressing short hairpin RNA (shRNA) negative control (LV-NC-shRNA) or lncRNA-H19 shRNA (LV-H19-shRNA). The ecESCs infected with LV-NC-shRNA and LV-H19-shRNA were subcutaneously implanted into forty 6- to 8-week-old female nude mice. The size and weight of the endometriotic implants were measured at 1, 2, 3, and 4 weeks after implantation and compared, and lncRNA H19 levels in endometriotic implants were evaluated using real-time polymerase chain reaction (RT-PCR). All nude mice survived the experimental period, and no significant differences in body weight were observed between the experimental group and the control group. All nude mice developed histologically confirmed subcutaneous endometriotic lesions with glandular structures and stroma after 1 week of implantation. The subcutaneous lesions in the LV-NC-shRNA group after 1, 2, 3, and 4 weeks of implantation were larger than those in the LV-H19-shRNA group, and lncRNA H19 levels in subcutaneous lesions in the LV-NC-shRNA group were significantly higher than those in the LV-H19-shRNA group. Knockdown of lncRNA H19 suppresses endometriosis in vivo. Further study is required to explore the underlying mechanism in the future.

The expression and significance of leukemia inhibitory factor, interleukin-6 and vascular endothelial growth factor in Chinese patients with endometriosis

OBJECTIVE

To observe the levels of leukemia inhibitory factor (LIF), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in blood, peritoneal fluid, ectopic endometrial tissue, and ectopic endometrial stromal cells of patients with endometriosis, and to compare expression of IL-6, LIF and VEGF expression between endometriotic and non-endometriotic patients underwent laparoscopic surgery.

METHODS

Thirty-one patients who underwent laparoscopic surgery for endometriosis in our hospital from January 2018 to January 2020 were included in the observation group, and 32 patients who underwent laparoscopic surgery for uterine fibroids, ovarian serous cystadenoma, and ovarian teratomas, were included in the control group. The levels of LIF, IL-6 and VEGF in the blood and peritoneal fluid of the two groups of patients were detected. The levels of LIF, IL-6 and VEGF in ectopic endometrial tissue and self-paired eutopic endometrial tissue, ectopic endometrial stromal cells and self-paired eutopic endometrial stromal cells of patients in the observation group were detected. After treating the primary cultured ectopic endometrial stromal cells with LIF and IL-6 alone or in combination, the changes of VEGF mRNA of ectopic endometrial stromal cells and the VEGF levels in the supernatant were observed.

RESULTS

The levels of LIF, IL-6 and VEGF in the blood and peritoneal fluid of the observation group were all higher than those of the control group (P < 0.05), and the levels of LIF, IL-6 and VEGF in the peritoneal fluid of the observation group were significantly higher than those in the blood (P < 0.05). In the observation group, the expression levels of LIF-mRNA and IL-6 mRNA in the ectopic endometrial tissue were higher than those in the self-paired eutopic endometrial tissues (P < 0.05), while the expression level of VEGF mRNA in the ectopic endometrial tissues was lower than that in the self-paired eutopic endometrial tissues (P < 0.05). Besides, the mRNA expression levels of LIF, IL-6 and VEGF in ectopic endometrial stromal cells of the observation group were all higher than those in the self-paired eutopic endometrial stromal cells (P < 0.05). After stimulating ectopic endometrial stromal cells with LIF, IL-6 and LIF + IL-6, respectively, the VEGF levels in the supernatant were all significantly higher than that in the blank control group (P < 0.05).

CONCLUSION

The LIF, IL-6 and VEGF levels in blood and peritoneal fluid were increased in patients with endometriosis, and increased LIF and IL-6 in ectopic endometriosis stromal cells can play a synergistic role in increasing the VEGF levels, which may be involved in the occurrence and development of endometriosis.

Mast Cells in Peritoneal Fluid From Women With Endometriosis and Their Possible Role in Modulating Sperm Function

Endometriosis is a local pelvic inflammatory process, frequently associated with infertility, with altered function of immune-related cells in the peritoneal environment. Mast cells are known to be key players of the immune system and have been recently involved in endometriosis and in infertility, with their mediators directly suppressing sperm motility. In this study, we evaluated the mast cell population and their mediators in the peritoneal fluid of infertile patients with endometriosis and their impact on human sperm motility. Peritoneal fluids, collected by laparoscopy from 11 infertile patients with endometriosis and 9 fertile controls were evaluated for the presence of mast cells, tryptase levels and their effect on sperm motility. Furthermore, an in vitro model of mast cells-sperm interaction in peritoneal fluid was set up, using LAD2 cell line as a mast cell model, and analyzed from a functional as well as a morphological point of view. Mast cell peritoneal fluid population and its main mediator, tryptase, is more represented in endometriosis confirming an involvement of these cells in this disease. Anyway it appears unlikely that tryptase enriched peritoneal fluid, which fails to inhibit sperm motility, could contribute to endometriosis associated infertility. Despite of this, sperm interaction with the mast cell surface (LAD2) induced a significantly mast cell-degranulation response in the peritoneal fluid from endometriosis which could directly modulate sperm function other than motility. This evidence lead us to suppose that there is, between these elements, an interrelationship which deserves further studies.

NK Cells as Potential Targets for Immunotherapy in Endometriosis

Endometriosis is a common gynecological disease defined by the presence of endometrial-like tissue outside the uterus, most frequently on the pelvic viscera and ovaries, which is associated with pelvic pains and infertility. It is an inflammatory disorder with some features of autoimmunity. It is accepted that ectopic endometriotic tissue originates from endometrial cells exfoliated during menstruation and disseminating into the peritoneum by retrograde menstrual blood flow. It is assumed that the survival of endometriotic cells in the peritoneal cavity may be partially due to their abrogated elimination by natural killer (NK) cells. The decrease of NK cell cytotoxic activity in endometriosis is associated with an increased expression of some inhibitory NK cell receptors. It may be also related to the expression of human leukocyte antigen G (HLA-G), a ligand for inhibitory leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) receptors. The downregulated cytotoxic activity of NK cells may be due to inhibitory cytokines present in the peritoneal milieu of patients with endometriosis. The role of NK cell receptors and their ligands in endometriosis is also confirmed by genetic association studies. Thus, endometriosis may be a subject of immunotherapy by blocking NK cell negative control checkpoints including inhibitory NK cell receptors. Immunotherapies with genetically modified NK cells also cannot be excluded.