Markers of oxidative stress in follicular fluid of women with endometriosis and tubal infertility undergoing IVF

Angiotensin II - AT1 receptor signalling regulates the plasminogen-plasmin system in human stromal endometrial cells increasing extracellular matrix degradation, cell migration and inducing a proinflammatory profile

The pivotal role of human endometrial stromal cells (hESCs) in the development of endometriosis lies in their ability to adopt a pro-invasive and proinflammatory profile upon migration to areas outside the uterus. However, the molecular mechanisms involved in these events remain unclear. In this study, we investigated how angiotensin II (Ang II) affects the plasminogen-plasmin system in hESCs, and the mechanisms underlying cell proliferation, migration, matrix degradation, and inflammation. Precursors, receptors, and peptidases involved in angiotensin metabolism increased significantly in Ang II-treated hESCs. The expression and activity of tissue (tPA)- and urokinase (uPA)- type plasminogen activators and the receptor for uPA (uPAR) were induced in the presence of Ang II. The up-regulation of tPA-uPA/uPAR pathway significantly contributes to heightened plasmin production both on the surface of hESCs and in their conditioned media. As a result, the plasmin generation induced by Ang II enhances the degradation of fibrin and matrix proteins, while also boosting hESC viability, proliferation, and migration through the up-regulation of growth factor expression. Notably, Ang II-induced hESC migration was dependent on the generation of active plasmin on cell surface. Ang II regulates oxidative and inflammatory signalling in hESCs primarily via NADPH oxidase and through the up-regulation of proinflammatory cytokines and adhesion molecules. Interestingly, Ang II receptor (AT1R) blockage, decreased plasmin generation, tPA-uPA/uPAR expression and hESC migration. Our results suggest that Ang II/AT1R axis regulates hESC proliferation and migration through tPA-uPA/uPAR pathway activation and plasmin generation. We propose the Ang II/AT1R axis as a potential target for endometriosis treatment.

The Role of One-Carbon Metabolism and Methyl Donors in Medically Assisted Reproduction: A Narrative Review of the Literature

One-carbon (1-C) metabolic deficiency impairs homeostasis, driving disease development, including infertility. It is of importance to summarize the current evidence regarding the clinical utility of 1-C metabolism-related biomolecules and methyl donors, namely, folate, betaine, choline, vitamin B12, homocysteine (Hcy), and zinc, as potential biomarkers, dietary supplements, and culture media supplements in the context of medically assisted reproduction (MAR). A narrative review of the literature was conducted in the PubMed/Medline database. Diet, ageing, and the endocrine milieu of individuals affect both 1-C metabolism and fertility status. In vitro fertilization (IVF) techniques, and culture conditions in particular, have a direct impact on 1-C metabolic activity in gametes and embryos. Critical analysis indicated that zinc supplementation in cryopreservation media may be a promising approach to reducing oxidative damage, while female serum homocysteine levels may be employed as a possible biomarker for predicting IVF outcomes. Nonetheless, the level of evidence is low, and future studies are needed to verify these data. One-carbon metabolism-related processes, including redox defense and epigenetic regulation, may be compromised in IVF-derived embryos. The study of 1-C metabolism may lead the way towards improving MAR efficiency and safety and ensuring the lifelong health of MAR infants.

ZnT 9 Involvement in Estradiol-Modulated Zinc Homeostasis of the Human Follicular Microenvironment

Female subfertility has been a growing concern for reproductive health. Assisted reproductive technologies make pregnancy possible, but the outcome rate is still suboptimal. Zinc is an essential factor for fertility and development. Zinc levels in follicular fluids were measured by electrochemical method, and we found that zinc in the follicular fluids was related to high-quality embryo rate (R = 0.39, p = 0.01). Basal estradiol levels and estradiol levels on the day of HCG injection were negatively correlated with zinc concentrations in the follicular fluid (R =  - 0.53, p < 0.001; R =  - 0.32, p < 0.05), and estradiol promoted ZnT 9 protein expression in cumulus granulosa cells in vitro and in vivo. When the zinc level was at 3.63-3.85 μg/mL, follicular fluid samples had the highest SOD activity. Therefore, zinc played an important role in improving oocyte development by increasing antioxidant capacity. Our results suggested that estradiol affected zinc homeostasis in follicles by controlling the expression of ZnT 9, which in turn influenced the potential of oocytes to develop into good-quality embryos. This study to provide tangible improvements to patient outcomes will make it a focus of both scientific and translational efforts in the future.

Exploring the Impact of Nickel Exposure on Female Fertility

Introduction Infertility affects an estimated 186 million individuals globally and is associated with numerous mental health issues. Trace elements are essential for reproductive health, yet the role of nickel in female fertility is not well understood. Previous research has shown conflicting evidence regarding nickel's impact on ovarian function and its potential to disrupt reproductive processes. Methods We utilized data from the National Health and Nutrition Examination Survey (NHANES) focusing on a cohort of 7,839 women, with an emphasis on 1,404 women aged 18 to 35. Logistic regression was employed to investigate the relationship between urinary nickel levels and fertility status, controlling for age, BMI, and race/ethnicity. Results The fertility analysis included 880 fertile and 106 infertile women, identifying age as a significant predictor of fertility status. Nickel exposure did not demonstrate a statistically significant association with fertility. The racial distribution within the groups showed a higher proportion of non-Hispanic White women in the fertile category and Mexican American women in the infertile group, although race was not a significant predictor in the regression model. Conclusions We found no significant relationship between nickel exposure and fertility status when adjusted for race, BMI, and age. Age was the only significant factor associated with fertility. These results highlight the complexity of the interplay between environmental exposures and reproductive health, suggesting that further research is necessary to elucidate the role of nickel and other trace elements in fertility.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Anti-inflammatory, antioxidant, antiangiogenic, and therapeutic efficacy of neroli oil in rats with endometriotic lesions

INTRODUCTION

Endometriosis is a serious health problem among women of reproductive age, with pelvic pain and infertility. Given the limited success of current treatments, this study explores Neroli oil (N.O.) effects on inflammation, oxidation, angiogenesis, and tissue remodeling implicated in endometriosis.

MATERIALS AND METHODS

Albino Wistar female rats were used to simulate an endometriosis model. Groups were established for comparison: a control, an endometriosis model, a N.O.-treated group, and a N.O.-treated group postendometriosis induction. The study focused on Tumor necrosis factor-alpha (TNF-α), Interleukin 6, Interleukin 8, vascular endothelial growth factor (VEGF), myeloperoxidase, Matrix metalloproteinase-1 (MMP-1), nitric oxide, superoxide dismutase, catalase, and anti-mullerian hormone values, as well as histopathological evaluations of endometriotic foci.

RESULTS

AMH values showed a significant increase in the endometriosis group treated with N.O. compared with the endometriosis group (p < 0,01).A statistically significant decrease was found in MMP-1 level in the endometriosis group that underwent N.O. (p < 0.001). Increased CAT (p < 0.0001) and decrease in nitric oxide (p < 0.01) are found in N.O.-treated endometriosis group. TNF-α levels in the endometriosis group showed a statistically significant increase in the endometriosis group when compared with the control and sham group (p < 0.001, p < 0.01 respectively). In our study, a statistically significant increase was observed in VEGF levels (p < 0.001) in endometriosis group and significant decrease in the N.O. administered endometriosis model group. Groups treated with N.O. showed decreased inflammation and congestion scores. Histopathological assessments demonstrated reduced inflammation and tissue remodeling signs in endometriotic foci.

CONCLUSION

This study highlights the potential of N.O. in the treatment of endometriosis, owing to its anti-inflammatory, antioxidant, and antiangiogenic properties that can disrupt chronic processes. Our findings lend support to utilization of herbal remedies for the management of endometriosis, thereby emphasizing the necessity for additional comprehensive investigations in the future.

Impact of endometriosis on the ovarian follicles

A significant body of evidence has supported a negative impact of endometriosis on ovarian follicles; however, the origin and relevance of this ovarian impairment in endometriosis is still a matter of debate. The ovarian damage can be caused by endometriosis itself or by surgeries aiming to remove endometriotic lesions. In this review, we summarized the existing knowledge on the mechanisms by which endometriosis can impact the ovarian follicles, from molecular to clinical points of view. From a molecular standpoint, the presence of endometriosis or its consequences can induce oxidative stress, inflammation, aberrant mitochondrial energy metabolism and inappropriate steroid production in granulosa cells, phenomena that may impair the quality of oocytes to variable degrees. These alterations may have clinical relevance on the accelerated exhaustion of the ovarian reserve, on the ovarian response to gonadotrophin stimulation in IVF cycles and on the competence of the oocytes. Critical points to be considered in current clinical practices related to fertility issues in endometriosis are discussed.

Selenium Content in the Gonads of Healthy Cats (Felis catus) and Cats with Impaired Homeostasis from the Warsaw Area (Poland)

The aim of the present study was to evaluate selenium content in the gonads of healthy cats and those with impaired homeostasis with the use of fluorescence spectroscopy. Higher concentrations of selenium were found in the gonads of the male domestic cats studied. The average content of this element in the testes of healthy males was: 0.59 mg·kg-1 while 0.47 mg·kg-1 wet weight was recorded in the ovaries of females. In the case of individuals with impaired homeostasis, higher values of selenium were found in the ovaries of obese females (0.40 mg·kg-1), while in the case of females with diagnosed malignancy of the mammary gland, the average values were lower and amounted to 0.31 mg·kg-1 wet weight of tissue. On the basis of statistical analysis, significant differences were found according to sex, age, and disturbed homeostasis of the individuals studied. An association was found between low Se in the gonads and obesity, as well as the presence of mammary gland neoplastic lesions. In addition, Se content was found to decrease with age in females, which can reduce resistance to oxidative stress.

Premature ovarian insufficiency: a review on the role of tobacco smoke, its clinical harm, and treatment

Premature ovarian insufficiency (POI) is a condition in which the quantity of follicles and the quality of oocytes gradually decrease. This results in an estrogen secretion disorder and abnormal follicle development, which can lead to related diseases, early onset of menopause, sexual dysfunction, and an increased risk of cardiovascular issues, osteoporosis, and depression, among others. This disease significantly impacts the physical and mental health and overall quality of life of affected women. Factors such as genetic abnormalities, oophorectomy, radiotherapy for malignancy, idiopathic conditions, and an unhealthy lifestyle, including smoking, can accelerate the depletion of the follicular pool and the onset of menopause. Extensive research has been conducted on the detrimental effects of tobacco smoke on the ovaries. This article aims to review the advancements in understanding the impact of tobacco smoke on POI, both in vivo and in vitro. Furthermore, we explore the potential adverse effects of common toxicants found in tobacco smoke, such as polycyclic aromatic hydrocarbons (PAHs), heavy metals like cadmium, alkaloids like nicotine and its major metabolite cotinine, benzo[a]pyrene, and aromatic amines. In addition to discussing the toxicants, this article also reviews the complications associated with POI and the current state of research and application of treatment methods. These findings will contribute to the development of more precise treatments for POI, offering theoretical support for enhancing the long-term quality of life for women affected by this condition.

How Can Selected Dietary Ingredients Influence the Development and Progression of Endometriosis?

Endometriosis is a chronic, hormone-dependent disease characterized by the presence of endometrial tissue in ectopic locations. Since the treatment options for this disease are still limited, and the cure rate is unsatisfactory, the search for ways to treat symptoms and modify the course of the disease is of key importance in improving the quality of life of patients with endometriosis. So far, the literature has shown that nutrition can influence endometriosis through hormonal modification and altering the inflammatory or oxidative response. Since the importance of nutrition in this disease is still a subject of scientific research, we aimed to summarize the current knowledge on the role of dietary modifications in endometriosis. Our review showed that nutrients with anti-inflammatory and antioxidant properties, including most vitamins and several trace elements, may influence the pathogenesis of endometriosis and can be considered as the nutrients preventing the development of endometriosis. However, despite the many discoveries described in this review, further interdisciplinary research on this topic seems to be extremely important, as in the future, it may result in the development of personalized therapies supporting the treatment of endometriosis.

Oxidative stress and female infertility: the role of follicular fluid soluble receptor of advanced glycation end-products (sRAGE) in women with endometriosis

Oxidative Stress (OS) relates to the pathophysiology of endometriosis by activation of the inflammation process in the ovary, abdomen, peritoneum and endometrium. Advanced Glycation end-products (AGEs) cause oxidative damage to the follicles of the ovary. This study aims to investigate the correlation of follicular fluid soluble receptor of AGEs (FF sRAGE) with fertility-related parameters in infertile women with endometriosis. From January 2012 to July 2015 twenty-four women diagnosed with mild to moderate endometriosis aged 28-38 years underwent assisted reproduction. sRAGE levels measured in FF were related to lifestyle factors, sociodemographic characteristics, gynaecological and obstetric parameters, hormonal status and fertilization. sRAGE was inversely associated with BMI (r = -0.503, p = 0.012). No significant association of sRAGE with age (p = 0.714) or alcohol consumption (p = 0.882) was found. Pearson's r correlation coefficient revealed that sRAGE was positively associated with serum AMH (r = 0.518, p = 0.009), FF AMH (r = 0.630, p = 0.001), number of follicles >15mm (r = 0.601, p = 0.002), total number of follicles aspirated (r = 0.698, p < 0.001), total number of MII oocytes obtained, (r = 0.757, p < 0.001) and the number of embryos with good embryo scoring (suitable for ET) (r = 0.522, p = 0.009). It seems that measurement of FF RAGE might be a useful predictive marker for IVF success in infertile women with endometriosis undergoing assisted reproduction.

The Pathological Role of miRNAs in Endometriosis

Association studies investigating miRNA in relation to diseases have consistently shown significant alterations in miRNA expression, particularly within inflammatory pathways, where they regulate inflammatory cytokines, transcription factors (such as NF-κB, STAT3, HIF1α), and inflammatory proteins (including COX-2 and iNOS). Given that endometriosis (EMS) is characterized as an inflammatory disease, albeit one influenced by estrogen levels, it is natural to speculate about the connection between EMS and miRNA. Recent research has indeed confirmed alterations in the expression levels of numerous microRNAs (miRNAs) in both endometriotic lesions and the eutopic endometrium of women with EMS, when compared to healthy controls. The undeniable association of miRNAs with EMS hints at the emergence of a new era in the study of miRNA in the context of EMS. This article reviews the advancements made in understanding the pathological role of miRNA in EMS and its association with EMS-associated infertility. These findings contribute to the ongoing pursuit of developing miRNA-based therapeutics and diagnostic markers for EMS.

The Influence of Follicular Fluid Metals on Assisted Reproduction Outcome

Infertility has become more common, with an increased exposure to toxic compounds including heavy metals (HM). Follicular fluid (FF) surrounds the developing oocyte in the ovary and can be analysed to assess metal content. The levels of twenty-two metals were measured in the FF of ninety-three females in a reproduction unit, and their influence on assisted reproduction technique (ART), were examined. The metals were determined by optical emission spectrophotometry. Low values of copper, zinc, aluminium, and calcium favour polycystic ovary syndrome. The relationships between the number of oocytes and metals: iron (rs=0.303; p=0.003) and calcium (rs=-0.276; p=0.007) are significant, as well as between the number of mature oocytes with iron (rs=0.319; p=0.002), calcium (rs=-0.307; p=0.003) and sodium (rs=-0.215; p=0.039) and are near to significance in the case of aluminium (rs=-0.198; p=0.057). In the group with a fertilisation rate ≤ 75%, 36% of the women presented calcium >176.62 mg/kg compared to the group with a fertilisation rate ≥ 75% where this percentage was only 10% (p=0.011). An excess of iron and calcium reduces the good quality embryo rate, and an excess of potassium impairs the blastocyst rate. If potassium is above 237.18 mg/kg and calcium is below 147.32 mg/kg, these conditions favour embryo implantation. Pregnancy is influenced by high potassium and low copper levels. Controlling exposure to toxic elements is recommended for all couples with reduced fertility or receiving an ART.

[Male infertility, environment and lifestyle]

BACKGROUND

Since the 1970s, there has been a quantitative and qualitative decline in sperm parameters. The main hypothesis to explain such a rapid evolution is the involvement of environmental and behavioral phenomena.

METHODS

A bibliographic search limited to English and French literature in men published before 7/2023 was carried out on the links between fertility and pollution, xenobiotics, tobacco, narcotics, cannabis, alcohol, weight, sport, sedentary lifestyle, sleep and anabolics.

RESULTS

Profound changes in lifestyle have occurred over the past 50 years: reduced sleep time, sedentary lifestyle, dietary changes, tobacco consumption, use of narcotics and anabolics. These changes have a proven impact on spermogram parameters, and should be corrected in an effort to optimize reproductive health. Other environmental parameters: pollution, exposure to heavy metals, exposure to xenobiotics, phthalates and pesticides… will be more difficult to exclude from patients' daily lives, but deserve to be taken more into account.

CONCLUSION

This review should help the urologist to assess and counsel patients in order to improve their reproductive health. These factors should be routinely investigated in infertile men.

Oxidative stress and inflammatory markers in ovarian follicular fluid of women with diminished ovarian reserve during in vitro fertilization

BACKGROUND

Follicular microenvironment has been proposed as an important factor for oocyte grown and maturation. We sought to evaluate the oxidative stress and inflammatory levels in follicular fluid (FF) and association with embryo quality in patients with diminished ovarian reserve (DOR).

METHODS

The current research included 46 DOR cases and 56 normal ovarian reserve (NOR) cases. Twelve representative oxidative stress markers and eight representative inflammatory factors were measured in the FF.

RESULTS

Oxidative stress markers total GSH (T-GSH) was decreased in the FF from women with DOR compared with that in NOR group (P = 0.041). More modest differences were observed for reduced GSH (rGSH) and rGSH/GSSG. Women with DOR compared to controls had higher level of TNF-α (P = 0.000) and lower level of IL-18 (P = 0.013). Correlation analysis revealed that GSSG was negatively correlated with normal fertilization rate in NOR group (r = -0.358, P = 0.008), and reduced GSH was negatively correlated with normal fertilization rate in DOR group (r = -0.299, P = 0.049). Moreover, as the regression analysis data showed, the GSSG level was significantly associated with embryo quality indicator.

CONCLUSIONS

The FF in DOR patients was accompanied by increased oxidative stress and inflammatory levels. Follicular development of women with DOR might be influenced by unusual IL-18 and TNF-α levels in FF. And oxidative stress marker GSSG in NOR group was a negative predictor for embryo quality.

The role of iron in the pathogenesis of endometriosis: a systematic review

STUDY QUESTION

What is the role of iron in the pathophysiology of endometriosis?

SUMMARY ANSWER

Iron excess is demonstrated wherever endometriotic tissues are found and is associated with oxidative stress, an inflammatory micro-environment, and cell damage; the iron-mediated oxidative stress is independently linked to subfertility, symptom severity, and malignant transformation.

WHAT IS KNOWN ALREADY

Iron is found in excess in endometriotic tissues, and multiple mechanisms have been studied and posited to explain this. It is clear that iron excess plays a vital role in promoting oxidative stress and cell damage. The evidence base is large, but no comprehensive reviews exist to summarize our understanding and highlight the overarching themes to further our understanding and suggest future directions of study for the field.

STUDY DESIGN SIZE DURATION

This systematic review with a thematic analysis retrieved studies from the PubMed, Embase, Web of Science, and Cochrane Library databases and searches were conducted from inception through to August 2022. Human and animal studies published in the English language were included and identified using a combination of exploded MeSH terms ('Iron' and 'Endometriosis') and free-text search terms ('Iron', 'Ferric', 'Ferrous', 'Endometriosis', 'Endometrioma').

PARTICIPANTS/MATERIALS SETTING METHODS

This review was reported in accordance with the PRISMA guidelines. All studies reporting original data concerning the role of iron or iron complexes in the pathophysiology of endometriosis were included. Studies that did not report original data or provided a review of the field were excluded. Bias analysis was completed for each included study by using the Newcastle-Ottawa scoring system.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 776 records identified and these were screened down to 53 studies which met the eligibility criteria, including 6 animal and 47 human studies, with 3556 individual participants. Iron excess is demonstrated in various tissues and fluids, including ovarian endometriomas, ovarian follicles, ectopic endometriotic lesions, and peritoneal fluid. Markers of oxidative stress are strongly associated with high iron levels, and aberrant expression of iron-transport proteins has been demonstrated. Abnormal resistance to ferroptosis is likely. Iron-mediated oxidative stress is responsible for a pro-inflammatory micro-environment and is linked to subfertility, symptom severity, and, possibly, malignant transformation.

LIMITATIONS REASONS FOR CAUTION

A minority of the included studies were of objectively low quality with a high risk of bias and may lead to misleading conclusions. Additionally, multiple studies failed to appropriately characterize the included patients by known confounding variables, such as menstrual cycle phase, which may introduce bias to the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Current literature depicts a central role of aberrant iron mechanics and subsequent oxidative stress in endometriosis. It is likely that iron excess is at least partly responsible for the persistence and proliferation of ectopic endometriotic lesions. As such, iron mechanics represent an attractive target for novel therapeutics, including iron chelators or effectors of the iron-oxidative stress pathway. There are significant gaps in our current understanding, and this review highlights and recommends several topics for further research. These include the role of iron chelation, resistance to ferroptosis, the relationship between iron excess and localized hypoxia, systemic iron pathophysiology in endometriosis, and the role of oxidative stress in malignant transformation.

STUDY FUNDING/COMPETING INTERESTS

J.W. and S.G.P. are supported by clinical fellowships at Liverpool University Hospital NHS Foundation trust. No additional funding was requested or required for the completion of this work. C.J.H. is supported by a Wellbeing of Women project grant (RG2137). D.K.H. is supported by a Wellbeing of Women project grant (RG2137) and an MRC clinical research training fellowship (MR/V007238/1). The authors have no conflicts of interest to declare.

REGISTRATION NUMBER

A protocol was prospectively registered with the PROSPERO database in August 2021 (CRD42021272818).

The Implications of Insufficient Zinc on the Generation of Oxidative Stress Leading to Decreased Oocyte Quality

Zinc is a transition metal that displays wide physiological implications ranging from participation in hundreds of enzymes and proteins to normal growth and development. In the reproductive tract of both sexes, zinc maintains a functional role in spermatogenesis, ovulation, fertilization, normal pregnancy, fetal development, and parturition. In this work, we review evidence to date regarding the importance of zinc in oocyte maturation and development, with emphasis on the role of key zinc-binding proteins, as well as examine the effects of zinc and reactive oxygen species (ROS) on oocyte quality and female fertility. We summarize our current knowledge about the participation of zinc in the developing oocyte bound to zinc finger proteins as well as loosely bound zinc ion in the intracellular and extracellular environments. These include aspects related to (1) the impact of zinc deficiency and overwhelming production of ROS under inflammatory conditions on the offset of the physiological antioxidant machinery disturbing biomolecules, proteins, and cellular processes, and their role in contributing to further oxidative stress; (2) the role of ROS in modulating damage to proteins containing zinc, such as zinc finger proteins and nitric oxide synthases (NOS), and expelling the zinc resulting in loss of protein function; and (3) clarify the different role of oxidative stress and zinc deficiency in the pathophysiology of infertility diseases with special emphasis on endometriosis-associated infertility.

Clinicopathological characteristics, molecular features and novel diagnostic strategies for the detection of malignant transformation of endometriosis (Review)

Endometriosis is a benign gynecological disease that affects women of reproductive age. Although malignant transformation of endometriosis is rare, physicians must be aware of this due to the high incidence of clear cell carcinoma of the ovary (CCC) in Japan. The most prevalent histological subtype of ovarian cancer is CCC (~70%) followed by endometrioid carcinoma (30%). The present review discusses the clinicopathological and molecular features of endometriosis-associated ovarian cancer (EAOC) as well as prospects for novel diagnostic strategies. Papers published between 2000 and 2022 in the PubMed and Google Scholar databases were included. Contents of the endometriotic cyst fluid may be involved in carcinogenesis, although the underlying mechanisms are largely unknown. Some studies have proposed a possible mechanism wherein excessive hemoglobin, heme and iron could cause an imbalance in intracellular redox homeostasis in endometriotic cells. Combined with DNA damage and mutations, the imbalances may induce the development of EAOC. Endometriotic cells evolve to adapt to the prolonged unfavorable oxidative microenvironmental stress. On the other hand, macrophages enhance the antioxidative defense mechanism and protect endometriotic cells against oxidative damage through intercellular crosstalk and signaling pathways. Therefore, changes in redox signaling, energy metabolism and the tumor immune microenvironment could be the key elements in the malignant transformation of certain endometriotic cell clones. Additionally, non-invasive bioimaging (i.e., magnetic resonance relaxometry) and biomarkers (i.e., tissue factor pathway inhibitor 2) may be promising tools for early-stage detection of the disease. In conclusion, the present review summarizes the latest advancements in research on the biological characteristics and early diagnosis of malignant transformation of endometriosis.

Current Understanding of and Future Directions for Endometriosis-Related Infertility Research with a Focus on Ferroptosis

BACKGROUND

To date, the development of therapy for endometriosis and disease-related infertility remains a major challenge. Iron overload caused by periodic bleeding is a hallmark of endometriosis. Ferroptosis is an iron- and lipid-reactive oxygen species-dependent type of programmed cell death that is distinct from apoptosis, necrosis, and autophagy. This review summarizes the current understanding of and future directions for the research and treatment of endometriosis and disease-related infertility, with the main focus on the molecular basis of ferroptosis in endometriotic and granulosa cells.

METHODS

Papers published between 2000 and 2022 in the PubMed and Google Scholar databases were included in this review.

RESULTS

Emerging evidence suggests that ferroptosis is closely linked to the pathophysiology of endometriosis. Endometriotic cells are characterized by ferroptosis resistance, whereas granulosa cells remain highly susceptible to ferroptosis, suggesting that the regulation of ferroptosis is utilized as an interventional target for research into the treatment of endometriosis and disease-related infertility. New therapeutic strategies are urgently needed to efficiently kill endometriotic cells while protecting granulosa cells.

CONCLUSIONS

An analysis of the ferroptosis pathway in in vitro, in vivo, and animal research enhances our understanding of the pathogenesis of this disease. Here, we discuss the role of ferroptosis modulators as a research approach and potential novel treatment for endometriosis and disease-related infertility.

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.

Glutathione during Post-Thaw Recovery Culture Can Mitigate Deleterious Impact of Vitrification on Bovine Oocytes

Vitrification of bovine oocytes can impair subsequent embryo development mostly due to elevated oxidative stress. This study was aimed at examining whether glutathione, a known antioxidant, can improve further embryo development when added to devitrified oocytes for a short recovery period. Bovine in vitro matured oocytes were vitrified using an ultra-rapid cooling technique on electron microscopy grids. Following warming, the oocytes were incubated in the recovery medium containing glutathione (0, 1.5, or 5 mmol L^-1) for 3 h (post-warm recovery). Afterwards, the oocytes were lysed for measuring the total antioxidant capacity (TAC), activity of peroxidase, catalase and glutathione reductase, and ROS formation. The impact of vitrification on mitochondrial and lysosomal activities was also examined. Since glutathione, added at 5 mmol L^-1, significantly increased the TAC of warmed oocytes, in the next set of experiments this dose was applied for post-warm recovery of oocytes used for IVF. Glutathione in the recovery culture did not change the total blastocyst rate, while increased the proportion of faster developing blastocysts (Day 6-7), reduced the apoptotic cell ratio and reversed the harmful impact of vitrification on the actin cytoskeleton. These results suggest that even a short recovery culture with antioxidant(s) can improve the development of bovine devitrified oocytes.

Effect of Antioxidant Supplementation on Endometriosis-Related Pain: A Systematic Review

PURPOSE OF REVIEW

This study was conducted to determine the effects of antioxidant supplementation on endometriosis-related chronic pelvic pain, dysmenorrhea, and dyspareunia.

METHODS

PubMed/MEDLINE, Scopus, and Cochrane Library databases and the Google Scholar search engine were searched from early 2012 to 2022 using appropriate keywords for clinical trials receiving antioxidant supplements and reporting endometriosis-related pelvic pain (PROSPERO registration number CRD42022318924). The qualities of the included studies were evaluated using the Joanna Briggs Institute (JBI) Checklists Critical Appraisal Tools and the National Institutes of Health (NIH) quality assessment tool for before-after (Pre-Post) study with no control group. This systematic review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guideline.

RESULTS

In this systematic review, 8 studies (5 RCTs and 3 non-comparative trials) published in 2012-2022 were included.

CONCLUSIONS

The studies we included showed promising results in the use of antioxidants in endometriosis-related pain. However, many scientific studies are needed for clear statements.

OXIDATIVE STRESS AND REPRODUCTIVE FUNCTION: Oxidative stress in polycystic ovary syndrome

In brief

A genetic, epigenetic, and environmental association exists between oxidative stress (OS) and polycystic ovary syndrome (PCOS), expressed in a multifaceted clinical profile. This review summarizes and discusses the role of OS in the pathogenesis of PCOS syndrome, focusing on metabolic, reproductive, and cancer complications.

Abstract

Oxidative stress (OS), an imbalance between oxidants and antioxidants in cells, is one of many factors playing essential roles in the pathogenesis of polycystic ovary syndrome (PCOS). PCOS is described mainly as a disproportion of reproductive hormones, leading to chronic anovulation and infertility in women. Interestingly, OS in PCOS may be associated with many disorders and diseases. This review focuses on characteristic markers of OS in PCOS and the relationship between OS and PCOS related to insulin resistance (IR), hyperandrogenemia, obesity, chronic inflammation, cardiovascular diseases, and cancer. Interestingly, in patients with PCOS, an increase in oxidative status and insufficient compensation of the increase in antioxidant status before any cardiovascular complications are observed. Moreover, free radicals promote carcinogenesis in PCOS patients. However, despite these data, it has not been established whether oxygen stress influences PCOS development or a secondary disorder resulting from hyperglycemia, IR, and cardiovascular and cancer complications in women.

Markers of Oxidative Stress in Obstetrics and Gynaecology-A Systematic Literature Review

Oxidative stress has been implicated in many diseases, including reproductive and pregnancy disorders, from subfertility to maternal vascular disease or preterm labour. There is, however, discrepancy within the standardized markers of oxidative stress in obstetrics and gynaecology in clinical studies. This review aims to present the scope of markers used between 2012 and 2022 to describe oxidative stress with regard to reproduction, pregnancy, and pregnancy-related issues. Despite the abundance of evidence, there is no consensus on the set of standardised markers of oxidative stress which poses a challenge to achieve universal consensus in order to appropriately triangulate the results.

Role of AMPK/mTOR, mitochondria, and ROS in the pathogenesis of endometriosis

Endometriosis is the presence of endometrial tissue outside the uterine cavity usually in the ovaries, fallopian tube, and pelvic cavity. It's a chronic enigmatic gynecological condition associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, and oxidative stress. This environment promotes cell survival through the binding of membrane receptors and subsequent cascading activation of intracellular kinases that stimulate a cellular response. In endometriosis, well-established signaling pathways, mTOR and AMPK, are altered via steroid hormones and other factors to promote cell growth, migration, and proliferation. This is accompanied by dysfunction in the mitochondria that increase energy production to sustain proliferation demands consequently leading to reactive oxygen species overproduction. This review aims to summarize the role of altered mTOR/AMPK signaling pathway, mitochondrial dysfunction, and reactive oxygen species overproduction along with providing therapeutic and diagnostic approaches. Highlighting these factors would provide a better understanding to reach a coherent theory for the pathogenesis of endometriosis.

Antioxidative, Anti-Inflammatory, Anti-Obesogenic, and Antidiabetic Properties of Tea Polyphenols-The Positive Impact of Regular Tea Consumption as an Element of Prophylaxis and Pharmacotherapy Support in Endometrial Cancer

Endometrial cancer (EC) is second only to cervical carcinoma among the most commonly diagnosed malignant tumours of the female reproductive system. The available literature provides evidence for the involvement of 32 genes in the hereditary incidence of EC. The physiological markers of EC and coexisting diet-dependent maladies include antioxidative system disorders but also progressing inflammation; hence, the main forms of prophylaxis and pharmacotherapy ought to include a diet rich in substances aiding the organism’s response to this type of disorder, with a particular focus on ones suitable for lifelong consumption. Tea polyphenols satisfy those requirements due to their proven antioxidative, anti-inflammatory, anti-obesogenic, and antidiabetic properties. Practitioners ought to consider promoting tea consumption among individuals genetically predisposed for EC, particularly given its low cost, accessibility, confirmed health benefits, and above all, suitability for long-term consumption regardless of the patient’s age. The aim of this paper is to analyse the potential usability of tea as an element of prophylaxis and pharmacotherapy support in EC patients. The analysis is based on information available from worldwide literature published in the last 15 years.

The Impact of Controlled Ovarian Stimulation on Serum Oxidative Stress Markers in Infertile Women with Endometriosis Undergoing ICSI

Endometriosis-related infertility is associated with oxidative stress (OS). The present study aims to compare serum OS markers of infertile women with endometriosis and controls during the follicular phase of the natural cycle (D1), after pituitary downregulation using a GnRH agonist (D2), after controlled ovarian stimulation (COS) on the day of human chorionic gonadotropin administration (D3), and on the day of oocyte retrieval (D4). One hundred and eight serum samples (58 controls and 35 early and 18 advanced endometriosis cases) were collected at these four timepoints. OS markers were compared among the groups and timepoints using a linear regression model with mixed effects and a post-test using orthogonal contrasts. The significance was set at 5%. We observed altered OS markers in the endometriosis patients during the D1, D2, D3, and D4 timepoints compared to the controls. The evidence of systemic OS in infertile patients with endometriosis during COS suggests the mobilization of potent antioxidants in an attempt to protect the oocyte from oxidative damage, especially on the day of oocyte retrieval.

Relation between Selenium and Female Fertility: A Systematic Review

OBJECTIVE

 To analyze the influence of selenium in female fertility.

DATA SOURCE

 A search was performed in the following databases: MEDLINE, Web of Science, Scopus, SciELO, LILACS, MDPI, ScienceDirect, and Europe PMC. The descriptors selected were "selenium" AND "female" AND "fertility". The search interval was from 1996 to 2021.

STUDY SELECTION

 The evaluation was performed independently by two reviewers, and a third reviewer confirmed the inclusion of papers in case of divergence between the first two reviewers. Papers were selected after the title and abstract were read, and those that met the eligibility criteria had the full text read.

DATA COLLECTION

 The following data was extracted: author, year of publication, country, type of study, objective, method, sample size, follow-up period, patients' mean age, inclusion and exclusion criteria, and concentration of serum and capillary selenium. The data was organized in chronological order of paper publication.

DATA SYNTHESIS

 The number of papers identified totaled 3,800, out of which 7 were included in the systematic review. The studies indicated a positive correlation between serum selenium and antioxidant concentration in the follicular fluid, reduction in antithyroid antibodies, oocyte production and follicle number.

CONCLUSION

 Selenium supplementation is promising in women with this micronutrient deficiency to promote improvement of the reproductive efficiency and prevent damage to the pregnancy. Further studies on this theme are still required.

Follicular fluid 8-Hydroxy-2-Deoxyguanosine (8-OHdG) as biomarker for oxidative stress in intracytoplasmic sperm injection

Oxidative stress (OS) is a situation that occurs as a result of un-equilibrium between reactive oxygen species (ROS) formation and the antioxidant defence system. 8-hydroxy-2-deoxyguanosine (8-OHdG), an oxidized form of deoxyguanosine, is found in higher levels in aging oocytes. In this cross-sectional study, we aimed to evaluate the effect of 8-OHdG on the intracytoplasmic sperm injection (ICSI). Follicular fluid (FF) samples were taken after removing the oocyte for later analysis of 8-OHdG. The couples participants were categorized according to the cause of subfertility into three groups (female factor, malefactor, and unexplained infertility). Further division according to pregnancy state was done to evaluate the precise role of 8-OHdG on pregnancy state and ICSI outcome. Result : This study showed that the 8-OHdG levels significantly higher in non-pregnant women (p<0.05). Correlation study showed that 8-OHdG level in follicular fluid is negatively correlating with the number of retrieved oocytes, metaphase two oocytes (MII), fertilized oocytes (2PN = two pronuclei), cleaved zygotes, good quality embryos, and the difference was statistically significant (p<0.05). Conclusion: The study revealed that the 8-OHdG level in follicular fluid negatively influences ICSI outcome and it is higher in non-pregnant women. J. Med. Invest. 69 : 112-116, February, 2022.

The Effect of Dietary Patterns on Clinical Pregnancy and Live Birth Outcomes in Men and Women Receiving Assisted Reproductive Technologies: A Systematic Review and Meta-Analysis

The nutritional status of reproductive-aged couples can have a significant impact on fertility status, but the effect of dietary patterns on pregnancy outcomes in people using assisted reproductive technologies (ARTs) is currently unknown. This review aimed to synthesize the published research investigating the relation between preconception dietary patterns and clinical pregnancy or live birth in men and women of reproductive age undergoing ART. Six electronic databases were systematically searched for original research published between January 1978 and June 2021. Original research reporting on the effect of predefined dietary patterns on either clinical pregnancy and/or live birth rates following in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in men and women aged 18-49 y was eligible for inclusion. Studies were assessed for risk of bias according to the Cochrane guidelines. Included studies underwent qualitative and quantitative synthesis using random-effects model meta-analyses. Thirteen studies (12 cohort studies, 1 randomized controlled trial) reporting on 3638 participants (93% female) were included in the review. All studies had a moderate-high risk of bias. In individual studies, maternal adherence to 4 dietary patterns [Mediterranean diet (RR: 1.22; 95% CI: 1.05, 1.43), novel profertility diet (OR: 1.43; 95% CI: 1.19, 1.72), Iranian traditional medicine diet (OR: 3.9; 95% CI: 1.2, 12.8), Dutch national dietary recommendations diet (OR: 1.65; 95% CI: 1.08, 2.52)] was associated with increased likelihood of achieving a clinical pregnancy, while 2 dietary patterns [novel profertility diet (OR: 1.53; 95% CI: 1.26, 1.85), Mediterranean diet (RR: 1.25; 95% CI: 1.07, 1.45)] were associated with increased probability of live birth. Meta-analyses showed an association between adherence to the Mediterranean dietary pattern and live birth across 2 studies (OR: 1.98; 95% CI: 1.17, 3.35; I2 = 29%, n = 355), but no association with clinical pregnancy. As the relation between dietary patterns and ART outcomes is currently inconsistent, higher-quality nutrition research is required to further explore this emerging field of interest (PROSPERO registration: CRD42020188194).

The associations of serum metals concentrations with the intermediate and pregnancy outcomes in women undergoing in vitro fertilization (IVF)

BACKGROUND

Toxic and essential trace elements are reported to have impact on female fertility. However, studies on the potential synergistic or antagonistic effects of metal mixtures on IVF outcomes remain limited.

OBJECTIVE

To evaluate whether serum concentrations of metals, individually and as mixtures, are associated with pregnancy outcomes in women undergoing IVF.

METHODS

In a prospective birth cohort study about IVF from the First Affiliated Hospital of Anhui Medical University (n = 1184), we measured the concentrations of serum metals by ICP-MS according to a previously established method. Oocyte/embryo development indicators and follow-up results were also collected. The individual and joint effects of metals were estimated using logistic regressions and Bayesian kernel machine regressions (BKMR).

RESULTS

At embryonic stage, we found negative associations between the serum lead (Pb) (β = -0.14, 95%CI: -0.32, -0.04) and cadmium (Cd) (β = -0.24, 95%CI: -0.39, -0.09) concentrations and the high-quality embryos rate; and positive associations between the serum cobalt (Co) (β = 0.18, 95%CI: 0.05, 0.31) and selenium (Se) (β = 0.17, 95%CI: 0.06, 0.41) concentrations and the MII rate. Regarding to the pregnancy outcomes, the serum Pb was negatively related with successful implantation (OR=0.85, 95%CI: 0.77, 0.94) and clinical pregnancy (OR=0.95, 95%CI: 0.91, 0.99); and positively associated with spontaneous abortion (OR=1.39, 95% CI: 1.02, 1.91). The BKMR analysis showed linear or parabolic associations between the metal mixtures and pregnancy outcomes, with Pb showing the highest posterior inclusion probabilities.

CONCLUSIONS

The toxic (Pb, Cd) and essential (Co, Se) metals could be incorporated as simultaneous predictors of IVF outcomes including potential antagonistic effects, in which Pb exhibits major contributions.

Oxidative stress and DNA damage status in couples undergoing in vitro fertilization treatment

This study examined the status of oxidative stress in 599 couples undertaking in vitro fertilization (IVF) treatment and its association with reproductive hormones, smoking, and outcomes. Oxidative stress biomarkers such as malondialdehyde, 8-hydroxy-2-deoxyguanosine, hydrogen peroxide (H₂O₂), catalase (CAT), and total antioxidant capacity (TAC) were determined in follicular fluid and seminal plasma. Tail moment (TM) was used to evaluate DNA damage in the sperm and granulosa cells. Reproductive hormones in serum and cotinine (COT) in urine, follicular fluid, and seminal plasma samples were determined. Separate multivariate linear regression was used to assess associations between levels of each oxidative stress biomarker and each hormone and smoking parameter (modeled as natural log-transformed). The findings indicate that some oxidative stress and DNA damage biomarkers played a role in disrupting certain reproductive hormones in women and their male partners either by overproducing reactive oxygen species or reducing antioxidant defense capacity. Although women were nonsmokers, COT levels > 50 and 10 µg/L in urine and follicular were observed in 5.7 and 1.7%, respectively. Levels of follicular fluid COT were positively associated with H₂O₂ and TM. We used log-binomial multivariate regression to estimate relative risks for the association between oxidative stress/DNA damage and IVF binary outcomes (fertilization rate > 50%, biochemical pregnancy, clinical pregnancy, and live birth). An increase in the CAT levels of follicular fluid was associated with a 48 and 41% decrease in the risk of poor fertilization rate (≤50%) and unsuccessful live birth, respectively. After the models were adjusted for hormonal factors, the associations remained the same, except that the elevated TAC in follicular fluid became significantly associated with a decrease of 42% in the risk of poor fertilization rate (≤50%). The higher antioxidant activity (CAT and TAC) in follicular fluid might positively impact specific IVF outcomes.

Inhibiting bridge integrator 2 phosphorylation leads to improved oocyte quality, ovarian health and fertility in aging and after chemotherapy in mice

Female ovaries degenerate about 20 years earlier than testes leading to reduced primordial follicle reserve and a reduction in oocyte quality. Here we found that bridge integrator 2 (BIN2) is enriched in mouse ovaries and oocytes and that global knockout of this protein improves both female fertility and oocyte quality. Quantitative ovarian proteomics and phosphoproteomics showed that Bin2 knockout led to a decrease in phosphorylated ribosomal protein S6 (p-RPS6), a component of the mammalian target of rapamycin pathway and greatly increased nicotinamide nucleotide transhydrogenase (NNT), the free-radical detoxifier. Mechanistically, we find that phosphorylation of BIN2 at Thr423 and Ser424 leads to its translocation from the membrane to the cytoplasm, subsequent phosphorylation of RPS6 and inhibition of Nnt translation. We synthesized a BIN2-penetrating peptide (BPP) designed to inhibit BIN2 phosphorylation and found that a 3-week BPP treatment improved primordial follicle reserve and oocyte quality in aging and after chemotherapy-induced premature ovarian failure without discernible side effects.

Impact of endometriosis on female fertility and the management options for endometriosis-related infertility in reproductive age women: a scoping review with recent evidences

Background

Endometriosis is a chronic inflammatory condition with varied presentation, which ultimately leads to chronic pelvic pain and infertility. It is a psychological and economic burden to the women and their families.

Main body of abstract

The literature search was performed on the following databases: MEDLINE, Google Scholar, Scopus, EMBASE, Global health, the COCHRANE library, and Web of Science. We searched the entirety of those databases for studies published until July 2020 and in English language. The literature search was conducted using the combination of the Medical Subject heading (MeSH) and any relevant keywords for “endometriosis related infertility and management” in different orders. The modalities of treatment of infertility in these patients are heterogeneous and inconclusive among the infertility experts. In this article, we tried to review the literature and look for the evidences for management of infertility caused by endometriosis. In stage I/II endometriosis, laparoscopic ablation leads to improvement in LBR. In stage III/IV, operative laparoscopy better than expectant management, to increase spontaneous pregnancy rates. Repeat surgery in stage III/IV rarely increases fecundability as it will decrease the ovarian reserve, and IVF will be better in these patients. The beneficial impact of GnRH agonist down-regulation in ART is undisputed. Dienogest is an upcoming and new alternative to GnRH agonist, with a better side effect profile. IVF + ICSI may be beneficial as compared to IVF alone. Younger patients planned for surgery due to pain or any other reason should be given the option of fertility preservation.

Short conclusion

In women with endometriosis-related infertility, clinician should individualize management, with patient-centred, multi-modal, and interdisciplinary integrated approach.

Does Exposure of Lead and Cadmium Affect the Endometriosis?

This study aimed to investigate the effects of blood lead levels (BLLs) and lead and cadmium exposure on endometriosis (EM). The study cohort consisted of female workers who underwent a lead-associated special medical examination between 1 January 2000 and 31 December 2004 (n = 26,542). The standard admission rate (SAR) and admission odds ratio (OR) for EM were calculated using the general population and noise-exposed groups, respectively, for the same period as the reference standards. The SAR for EM was 1.24 (95% confidence interval (CI): 1.03-1.48) in lead-exposed workers and 1.44 (95% CI: 1.11-1.85) in workers with BLLs < 5 μg/dL when compared with that of the general population. Admission ORs of EM in lead-exposed workers and those with BLLs < 5 μg/dL were statistically higher than those of noise-exposed workers (OR, 1.40; 95% CI, 1.15-1.70 and OR, 1.48; 95% CI, 1.11-1.98, respectively). The relative excess risk due to interaction of lead and cadmium was 0.33. Lead exposure was associated with EM admission. EM admission in lead-exposed workers with BLLs < 5 μg/dL was statistically higher than that of the general population and noise-exposed workers. Co-exposure to lead and cadmium has a synergistic effect with EM.

Altered Follicular Fluid Metabolic Pattern Correlates with Female Infertility and Outcome Measures of In Vitro Fertilization

Nearly 40-50% of infertility problems are estimated to be of female origin. Previous studies dedicated to the analysis of metabolites in follicular fluid (FF) produced contrasting results, although some valuable indexes capable to discriminate control groups (CTRL) from infertile females (IF) and correlate with outcome measures of assisted reproduction techniques were in some instances found. In this study, we analyzed in blind FF of 35 control subjects (CTRL = patients in which inability to obtain pregnancy was exclusively due to a male factor) and 145 IF (affected by: endometriosis, n = 19; polycystic ovary syndrome, n = 14; age-related reduced ovarian reserve, n = 58; reduced ovarian reserve, n = 29; unexplained infertility, n = 14; genetic infertility, n = 11) to determine concentrations of 55 water- and fat-soluble low molecular weight compounds (antioxidants, oxidative/nitrosative stress-related compounds, purines, pyrimidines, energy-related metabolites, and amino acids). Results evidenced that 27/55 of them had significantly different values in IF with respect to those measured in CTRL. The metabolic pattern of these potential biomarkers of infertility was cumulated (in both CTRL and IF) into a Biomarker Score index (incorporating the metabolic anomalies of FF), that fully discriminated CTRL (mean Biomarker Score value = 4.00 ± 2.30) from IF (mean Biomarker Score value = 14.88 ± 3.09, p < 0.001). The Biomarker Score values were significantly higher than those of CTRL in each of the six subgroups of IF. Posterior probability curves and ROC curve indicated that values of the Biomarker Score clustered CTRL and IF into two distinct groups, based on the individual FF metabolic profile. Furthermore, Biomarker Score values correlated with outcome measures of ovarian stimulation, in vitro fertilization, number and quality of blastocysts, clinical pregnancy, and healthy offspring. These results strongly suggest that the biochemical quality of FF deeply influences not only the effectiveness of IVF procedures but also the following embryonic development up to healthy newborns. The targeted metabolomic analysis of FF (using empowered Redox Energy Test) and the subsequent calculation of the Biomarker Score evidenced a set of 27 low molecular weight infertility biomarkers potentially useful in the laboratory managing of female infertility and to predict the success of assisted reproduction techniques.

Objective sleep duration and timing predicts completion of in vitro fertilization cycle

PURPOSE

To examine associations between objectively measured sleep duration and sleep timing with odds of completion of an in vitro fertilization (IVF) cycle.

METHODS

This prospective cohort study enrolled 48 women undergoing IVF at a large tertiary medical center between 2015 and 2017. Sleep was assessed by wrist-worn actigraphy, 1-2 weeks prior to initiation of the IVF cycle. Reproductive and IVF cycle data and demographic and health information were obtained from medical charts. Sleep duration, midpoint, and bedtime were examined in relation to IVF cycle completion using logistic regression models, adjusted for age and anti-Müllerian hormone levels. A sub-analysis excluded women who worked non-day shifts to control for circadian misalignment.

RESULTS

The median age of all participants was 33 years, with 29% of women >35 years. Ten women had an IVF cycle cancelation prior to embryo transfer. These women had shorter sleep duration, more nocturnal awakenings, lower sleep efficiency, and later sleep timing relative to those who completed their cycle. Longer sleep duration was associated with lower odds of uncompleted IVF cycle (OR = 0.88; 95%CI 0.78, 1.00, per 20-min increment of increased sleep duration). Women with later sleep midpoint and later bedtime had higher odds of uncompleted cycle relative to those with earlier midpoint and earlier bedtime; OR = 1.24; 95%CI 1.09, 1.40 and OR = 1.33; 95%CI 1.17, 1.53 respectively, for 20-min increments. These results were independent of age, anti-Müllerian hormone levels, or sleep duration, and remained significant after exclusion of shift-working women.

CONCLUSIONS

Shorter sleep duration and later sleep timing increase the odds of uncompleted cycles prior to embryo transfer.

The effect of follicular fluid selenium concentration on oocyte maturation in women with polycystic ovary syndrome undergoing in vitro fertilization/Intracytoplasmic sperm injection: A cross-sectional study

BACKGROUND

A high level of free radicals and oxidative substances in women with polycystic ovary syndrome (PCOS) can affect the ovaries through oxidative stress. Antioxidants such as selenium, a vital trace element in human health, can improve the prognosis of PCOS by reducing oxidative stress.

OBJECTIVE

This study was performed due to the lack of comprehensive information about selenium concentration in follicular fluid and its effect on the oocyte count and quality in infertile women with PCOS.

MATERIALS AND METHODS

In this cross-sectional study, 78 women with PCOS referred to Umm-al-Banin Infertility Clinic Center, Ganjavian Hospital, Dezful, Iran for in-vitro fertilization from March to November 2019 were enrolled. After ovarian stimulation with the antagonist protocol, the oocytes were retrieved under transvaginal ultrasound in in-vitro fertilization/intracytoplasmic sperm injection cycles, and selenium concentrations were measured in the follicular fluid using an atomic absorption method by spectrophotometer device. Oocyte count and morphology were evaluated using inverted optical microscopy.

RESULTS

There were no significant differences between follicular fluid selenium concentrations in terms of the total number of oocytes and immature oocytes in the metaphase I and germinal vesicle stages. However, a significantly reduced number of metaphase II oocytes was observed at selenium levels < 40 μg/dL (p = 0.001).

CONCLUSION

Based on our results, low levels of follicular selenium concentration in infertile women with PCOS can reduce the quality and potency of oocyte maturation.

Follicular Fluid Zinc Level and Oocyte Maturity and Embryo Quality in Women with Polycystic Ovary Syndrome

Background:

Polycystic ovary syndrome (PCOS) is considered to be one of the most common endocrine disorders in women of reproductive age. Zinc, a vital trace element in the body, plays a key role in maintaining health, especially due to its antioxidant role. On the other hand, lack of antioxidants and oxidative stress can adversely affect oocytes quality and consequently fertility rate. The available studies that report the effect of follicular fluid (FF) zinc in terms of the number and quality of the oocytes in infertile women with PCOS, are few and not consistent. We decided to investigate this issue.

Materials and Methods:

In this cross-sectional study, from the women with PCOS referring to Omolbanin Hospital, Dezful, Iran (February to December 2019), a total of 90 samples (follicular fluid, oocytes, and embryos) were collected from those who had undergone in vitro fertilization (IVF). To measure zinc level in follicular fluid, high performance liquid chromatograpy (HPLC) was utilized. Also, oocytes maturity and embryos quality evaluation was performed using inverted optical microscopy. One-way ANOVA and Fisher’s least significant difference (LSD) were used for data analysis.

Results:

The amount of FF zinc was not associated with any significant differences in the number of oocytes and metaphase I (MI) and germinal vesicle (GV) oocytes, but a significant decrease was observed in the number of metaphase II (MII) oocytes at zinc values less than 35 µg/dL. The FF zinc levels less than 35 µg/dL were also significantly associated with decreased embryo quality

Conclusion:

A significant relationship was found between the level of FF zinc and the quality and the number of oocytes taken from the ovaries of infertile patients with PCOS history who were candidates for IVF treatment as well as the number of high quality embryos.

Zinc

Since the discovery of manifest Zn deficiency in 1961, the increasing number of studies demonstrated the association between altered Zn status and multiple diseases. In this chapter, we provide a review of the most recent advances on the role of Zn in health and disease (2010-20), with a special focus on the role of Zn in neurodegenerative and neurodevelopmental disorders, diabetes and obesity, male and female reproduction, as well as COVID-19. In parallel with the revealed tight association between ASD risk and severity and Zn status, the particular mechanisms linking Zn2+ and ASD pathogenesis like modulation of synaptic plasticity through ProSAP/Shank scaffold, neurotransmitter metabolism, and gut microbiota, have been elucidated. The increasing body of data indicate the potential involvement of Zn2+ metabolism in neurodegeneration. Systemic Zn levels in Alzheimer's and Parkinson's disease were found to be reduced, whereas its sequestration in brain may result in modulation of amyloid β and α-synuclein processing with subsequent toxic effects. Zn2+ was shown to possess adipotropic effects through the role of zinc transporters, zinc finger proteins, and Zn-α2-glycoprotein in adipose tissue physiology, underlying its particular role in pathogenesis of obesity and diabetes mellitus type 2. Recent findings also contribute to further understanding of the role of Zn2+ in spermatogenesis and sperm functioning, as well as oocyte development and fertilization. Finally, Zn2+ was shown to be the potential adjuvant therapy in management of novel coronavirus infection (COVID-19), underlining the perspectives of zinc in management of old and new threats.

Cosmetic and personal care product use, urinary levels of parabens and benzophenones, and risk of endometriosis: results from the EndEA study

AIM

To explore the relationship of urinary concentrations of different congeners of benzophenones and parabens with the utilization of cosmetics and personal care products (PCPs) and their impact on the risk of endometriosis, and to evaluate the influence of oxidative stress on associations found.

METHODS

This case-control study comprised a subsample of 124 women (35 cases; 89 controls). Endometriosis was confirmed (cases) or ruled out (controls) by laparoscopy, with visual inspection of the pelvis and biopsy of suspected lesions (histological diagnosis). Urinary concentrations of benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxibenzophenone (4-OH-BP), methyl- (MeP), ethyl- (EtP), propyl- (PrP), and butyl-paraben (BuP), and biomarkers of oxidative stress [lipid peroxidation (TBARS) and total antioxidant power (TAP)] were quantified. Information was gathered on the frequency of use of cosmetics and PCPs. Associations between the frequency of cosmetics/PCP use, urinary concentrations of benzophenones and parabens, oxidative stress, and endometriosis risk were explored in logistic and linear multivariable regression analyses.

RESULTS

The frequency of utilization of certain cosmetics and PCPs was significantly associated with urinary concentrations of benzophenones and parabens. After adjustment for potential confounders, the risk of endometriosis was increased in women in the second versus first terciles of MeP (OR = 5.63; p-value<0.001), BP-1 (OR = 5.12; p-value = 0.011), BP-3 (OR = 4.98; p-value = 0.008), and ƩBPs (OR = 3.34; p-value = 0.032). A close-to-significant relationship was observed between TBARS concentrations and increased endometriosis risk (OR = 1.60, p-value = 0.070) and an inverse association between TAP concentrations and this risk (OR = 0.15; p-value = 0.048). Oxidative stress results did not modify associations observed between benzophenone/paraben exposure and endometriosis risk.

CONCLUSIONS

Our findings indicate that the frequency of cosmetics and PCP utilization is a strong predictor of exposure to certain benzophenone and paraben congeners. These compounds may increase the risk of endometriosis in an oxidative stress-independent manner. Further studies are warranted to corroborate these findings.

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.

Altered transcriptome in cumulus cells of infertile women with advanced endometriosis with and without endometrioma

RESEARCH QUESTION

Is the transcriptome of cumulus cells of infertile women with advanced endometriosis (EIII/IV), with and without endometrioma, altered?

DESIGN

In this prospective case-control study, next-generation RNA sequencing was used to compare the transcript profile of cumulus cells among infertile patients undergoing ovarian stimulation for intracytoplasmic sperm injection with EIII/IV, with (n = 9) and without endometrioma (n = 9), and controls (n = 9). An in-silico enrichment analysis was conducted to establish the possibly altered pathways in cumulus cells of patients with endometriosis.

RESULTS

Most of the differentially expressed genes (DEG) were found when cumulus cells from women with EIII/IV with endometrioma were compared with controls (DEG, n = 461). In women with EIII/IV without endometrioma, only 66 DEG were verified compared with controls. The enrichment analysis showed that some DEG in cumulus cells of endometriosis are involved in important pathways for the oocyte competence acquisition, such as oxidative phosphorylation, metabolism, mitochondrial function, acetylation and steroid biosynthesis. No DEG were found when cumulus cells from women with EIII/IV with and without endometrioma were compared.

CONCLUSION

RNA sequencing results suggest that cumulus cells of infertile women with EIII/IV have an altered transcriptome, regardless of endometrioma. The present findings offer a better understanding of the genes and molecular mechanisms that may be involved in endometriosis-related infertility, mostly in the oocyte competence acquisition process.

Variability of essential and non-essential trace elements in the follicular fluid of women undergoing in vitro fertilization (IVF)

Both essential and non-essential elements have been associated with female reproductive function in epidemiologic investigations, including among IVF populations. To date, most investigators have used blood or urine to assess biomarkers of exposure, with few employing ovarian follicular fluid (FF). FF may offer a more direct "snapshot" of the oocyte microenvironment than blood or urine, however previous studies report follicle-to-follicle variability in FF constituents that may contribute to exposure misclassification. Our objectives were to investigate sources of trace element variability, to estimate FF biomarker reliability among women undergoing IVF (n = 34), and to determine the minimum number of follicles required to estimate subject-specific mean concentrations. We measured As, Hg, Cd, Pb, Cu, Mn, Se, and Zn in FF samples using inductively coupled plasma tandem mass spectrometry. Inter-subject (between-women) variability contributed most of the variability in FF element concentrations, with ovarian, follicular, and analytical as smaller sources of variability. The proportion of variability attributable to sources between-follicles differed by age, body mass index (BMI), race, and cigarette smoking for Cu, Se, and Zn, by BMI and cigarette smoking for As, by primary infertility diagnosis for Hg, Cu, Se, and Zn, and by ovarian stimulation protocol for Mn and Se. Four to five individual follicles were sufficient to estimate subject-specific mean Cu, Se, and Zn concentrations, while >14 were necessary for As, Hg, Cd, Pb, and Mn. Overall, our results suggest that FF is a suitable source of biomarkers of As and Hg exposure in ovarian follicles. Although limited in size, our study offers the most comprehensive exploration of biological variation in FF trace elements to date and may provide guidance for future studies of ovarian trace element exposures.

Melatonin Alleviates Hypoxia-Induced Apoptosis of Granulosa Cells by Reducing ROS and Activating MTNR1B-PKA-Caspase8/9 Pathway

In mammalian ovaries, the avascular environment within follicular cavity is supposed to cause hypoxic status in granulosa cells (GCs), leading to apoptotic cell death accompanied by cumulative reactive oxygen species (ROS) production. Melatonin (N-acetyl-5-methoxytryptamine, MT), a broad-spectrum antioxidant that exists in porcine follicle fluid, was suggested to maintain GCs survival under stress conditions. In this study, using the established hypoxic model (1% O₂) of cultured porcine GCs, we explored the effect of MT on GCs apoptosis. The results showed that MT restored cell viability and reduced the apoptosis of GCs during hypoxia exposure. In addition, GCs treated with MT exhibited decreased ROS levels and increased expression of antioxidant enzymes including heme oxygenase-1 (HO-1), glutathione S-transferase (GST), superoxide dismutase 1 (SOD1), and catalase (CAT) upon hypoxia incubation. Moreover, the hypoxia-induced expression of cleaved caspase 3, 8, and 9 was significantly inhibited after MT treatment. In contrast, blocking melatonin receptor 2 (MTNR1B) with a competitive antagonist 4-phenyl-2-propionamidotetralin (4P-PDOT) diminished the inhibitory effects of MT on caspase 3 activation. By detecting levels of protein kinase (PKA), a downstream kinase of MTNR1B, we further confirmed the involvement of MT–MTNR1B signaling in mediating GCs protection during hypoxia stress. Together, the present data provide mechanistic evidence suggesting the role of MT in defending GCs from hypoxia-induced apoptosis.

Nonhormonal Treatment for Endometriosis Focusing on Redox Imbalance

The aim of this review is to investigate the oxidant/antioxidant status and its regulatory mechanisms in patients with endometriosis and to summarize the antioxidant therapy as an alternative to hormonal therapy for endometriosis. Each keyword alone or in combination was used to search from PubMed and Embase by applying the filters of the title and the publication years between January 2000 and March 2020. Endometriosis is a chronic inflammatory disease characterized by repeated episodes of hemorrhage. Methemoglobin in repeated hemorrhage produces large amounts of superoxide anion via the autoxidation of hemoglobin. Excessive free-radical production causes redox imbalance, leading to inadequate antioxidant defenses and damage to endometrial cells, but may contribute to endometrial cell growth and survival through activation of various signaling pathways. In addition, to overcome excessive oxidative stress, estradiol participates in the induction of antioxidants such as superoxide dismutase in mitochondria. Several antioxidants that suppress free radicals may be effective in endometriosis-related pain. We searched for 23 compounds and natural substances that could reduce the pain caused by superoxide/reactive oxygen species in basic research and animal models. Next, we built a list of 16 drugs that were suggested to be effective against endometriosis other than hormone therapy in preclinical studies and clinical trials. Of the 23 and 16 drugs, 4 overlapping drugs could be potential candidates for clinically reducing endometriosis-related pain caused by superoxide anion/reactive oxygen species. These drugs include polyphenols (resveratrol and polydatin), dopamine agonists (cabergoline), and statins (simvastatin). However, no randomized controlled trials have evaluated the efficacy of these drugs. In conclusion, this review summarizes the following 2 points: superoxide anion generation by methemoglobin is enhanced in endometriosis, resulting in redox imbalance; and some compounds and natural substances that can suppress free radicals may be effective in endometriosis-related pain. Further randomized clinical trials based on larger series are mandatory to confirm the promising role of antioxidants in the nonhormonal management of endometriosis.

Transferrin and antioxidants partly prevented mouse oocyte oxidative damage induced by exposure of cumulus-oocyte complexes to endometrioma fluid

Background

Exposure of oocytes to the endometrioma fluid has an adverse effect on embryonic quality. To determine whether adding transferrin and antioxidants to culture medium could counteract detrimental effects on mouse cumulus-oocyte complexes (COCs) induced by exposure to endometrioma fluid or not, we conducted an in vitro cross-sectional study using human and mouse COCs.

Methods

Eighteen women who had their oocytes exposed to endometrioma fluid during oocyte retrieval were enrolled. COCs from superovulated ICR female mice were collected. They were first exposed to human endometrioma fluid and then treated by transferrin and/or antioxidants (cysteamine + cystine). Subsequently, COCs function was assessed by molecular methods.

Results

This study observed that human COCs inadvertently exposed to endometrioma fluid in the in vitro fertilization (IVF) group led to a lower good quality embryo rate compared to intracytoplasmic sperm injection (ICSI) group. Exposure of mouse COCs to endometrioma fluid accelerated oocyte oxidative damage, evidenced by significantly reduced CCs viability, defective mitochondrial function, decreased GSH content and increased ROS level, associated with the significantly higher pro-portion of abnormal spindles and lower blastocyst formation (p < 0.05, respectively). This damage could be recovered partly by treating COCs with transferrin and antioxidants (cysteamine + cystine).

Conclusions

Transferrin and antioxidants could reduce the oxidative damage caused by COCs exposure to endometrioma fluid. This finding provides a promising new possibility for intervention in the human oocyte oxidative damage process induced by endometrioma fluid during oocyte pick-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-020-00738-0.

miR-532-3p: a possible altered miRNA in cumulus cells of infertile women with advanced endometriosis

RESEARCH QUESTION

Is the profile of microRNA (miRNA) altered in cumulus cells of infertile women with early (EI/II) and advanced (EIII/IV) endometriosis?

DESIGN

In this prospective case-control study, a miRNA profile including 754 targets was evaluated in samples of cumulus cells from infertile women with endometriosis (5 EI/II, 5 EIII/IV) and infertile controls (5, male and/or tubal factor) undergoing ovarian stimulation for intracytoplasmic sperm injection, using TaqMan® Array Human MicroRNA Cards A and B. The groups were compared with Kruskal-Wallis test, followed by Benjamini-Hochberg correction and Dunn's post hoc test. An in silico enrichment analysis was performed to list the possibly altered pathways in which the altered miRNA target genes are involved.

RESULTS

Only the miRNA miR-532-3p showed significant differences among the analysed groups, being down-regulated in the EIII/IV group compared with the infertile control group, as well as compared with the EI/II group. The enrichment analysis showed that some genes regulated by this miRNA are involved in important pathways for the acquisition of oocyte competence, such as the oxytocin, calcium, Wnt, FoxO, ErbB and Ras signalling pathways, as well as the oocyte meiosis pathway.

CONCLUSION

The present findings bring new perspectives to understanding the follicular microenvironment of infertile women with different stages of endometriosis. It is suggested that the dysregulation of miR-532-3p may be a potential mechanism involved in the aetiopathogenesis of endometriosis-related infertility. Further studies are needed to evaluate these pathways in cumulus cells of infertile women with the disease, as well as their impact on the acquisition of oocyte competence.

Seafood consumption is associated with higher follicular fluid arsenic (As) and mercury (Hg) concentrations in women undergoing in vitro fertilization (IVF)

Human exposure to non-essential toxic metals such as cadmium (Cd), mercury (Hg), and lead (Pb), and metalloids such as arsenic (As) commonly occurs through diet. Toxic trace element exposures have been reported in association with fertility and fecundity in epidemiologic studies even at low to moderate levels. While most previous studies employed blood and urine biomarkers of exposure, few have assessed toxic trace elements in ovarian follicular fluid (FF), which surrounds the developing oocyte and hence may better reflect concentrations potentially affecting reproductive outcomes. Our objective was to identify dietary predictors of FF toxic trace elements in n = 56 women (mean age: 38.3 years) undergoing in vitro fertilization (IVF) at the University of California at San Francisco. We determined As, Hg, Cd, and Pb in 197 FF specimens, collected on the day of oocyte retrieval, using inductively coupled plasma tandem mass spectrometry. A comprehensive food frequency questionnaire was used to assess the weekly and annual dietary "patterns" of participants. Consumption of specific seafood items and turkey were correlated with individual FF toxic trace elements. We also found that each unit higher seafood consumption in the past week dominated by mollusks, shrimp, and bass was associated with 60% higher FF As (95% confidence interval (CI): 25%, 105%) and FF Hg (95%CI: 7%, 136%) concentrations. Higher annual seafood consumption dominated by urchin, crab, and trout was associated with 16% higher FF As (95%CI: -2%, 38%) and 31% higher FF Hg (95%CI: 7%, 60%) concentrations per unit intake. No associations were noted between diet and Cd and Pb levels in FF. Overall, our results suggest that higher seafood consumption contributes to elevated levels of As and Hg in FF. These findings are consistent with previous IVF studies that assessed toxic trace element exposures in blood and urine. To our knowledge, this is the first study to report that diet might be a source of As, Hg, Cd, and Pb in FF.