Systemic oxidative stress could predict assisted reproductive technique outcome

The complementary seminovaginal microbiome in health and disease

Infertility, adverse pregnancy outcomes and genital infections are global concerns. The reproductive tract microbiome appears to play a crucial role in the physiology of both the female and male reproductive tracts. Despite the presence of thousands of microbes in body fluids shared during unprotected sexual intercourse, they have traditionally been studied separately, with greater emphasis on the female (mostly vaginal) microbiome, and the interaction between these microbiomes in a sexually active couple has been overlooked. This review introduces the concept of the 'seminovaginal microbiome' - the collective microbiota of both partners, transferred and shared during sexual interaction. By synthesizing the existing body of next-generation sequencing-based literature, this review establishes the first holistic view of how these microbiomes interact, influence reproductive health and affect assisted reproductive technique outcomes, as well as the occurrence of microbe-associated diseases such as sexually transmitted infections, prostatitis, bacterial vaginosis and candidiasis. Additionally, the microbial interplay in homosexual couples and transgender individuals is discussed.

Integrative Assessment of Seminal Plasma Biomarkers: A Narrative Review Bridging the Gap between Infertility Research and Clinical Practice

Infertility represents a significant global health challenge impacting millions of couples worldwide. Approximately half of all infertile couples exhibit compromised semen quality, indicative of diminished male fertility. While the diagnosis of male infertility traditionally relies on semen analysis, its limitations in providing a comprehensive assessment of male reproductive health have spurred efforts to identify novel biomarkers. Seminal plasma, a complex fluid containing proteins, lipids, and metabolites, has emerged as a rich source of such indicators. Reproduction depends heavily on seminal plasma, the primary transporter of chemicals from male reproductive glands. It provides a non-invasive sample for urogenital diagnostics and has demonstrated potential in the identification of biomarkers linked to illnesses of the male reproductive system. The abundance of seminal proteins has enabled a deeper understanding of their biological functions, origins, and differential expression in various conditions associated with male infertility, including azoospermia, asthenozoospermia, oligozoospermia, teratozoospermia, among others. The true prevalence of male infertility is understated due to the limitations of the current diagnostic techniques. This review critically evaluates the current landscape of seminal plasma biomarkers and their utility in assessing male infertility. Βy bridging the gap between research and clinical practice, the integrative assessment of seminal plasma biomarkers offers a multimodal approach to comprehensively evaluate male infertility.

Altered Energy Metabolism, Mitochondrial Dysfunction, and Redox Imbalance Influencing Reproductive Performance in Granulosa Cells and Oocyte During Aging

Female fertility decreases during aging. The development of effective therapeutic strategies to address the age-related decline in oocyte quality and quantity and its accurate diagnosis remain major challenges. In this review, we summarize our current understanding of the study of aging and infertility, focusing primarily on the molecular basis of energy metabolism, mitochondrial function, and redox homeostasis in granulosa cells and oocytes, and discuss perspectives on future research directions. Mitochondria serve as a central hub sensing a multitude of physiological processes, including energy production, cellular redox homeostasis, aging, and senescence. Young granulosa cells favor glycolysis and actively produce pyruvate, NADPH, and other metabolites. Oocytes rely on oxidative phosphorylation fueled by nutrients, metabolites, and antioxidants provided by the adjacent granulosa cells. A reduced cellular energy metabolism phenotype, including both aerobic glycolysis and mitochondrial respiration, is characteristic of older female granulosa cells compared with younger female granulosa cells. Aged oocytes become more susceptible to oxidative damage to cells and mitochondria because of further depletion of antioxidant-dependent ROS scavenging systems. Molecular perturbations of gene expression caused by a subtle change in the follicular fluid microenvironment adversely affect energy metabolism and mitochondrial dynamics in granulosa cells and oocytes, further causing redox imbalance and accelerating aging and senescence. Furthermore, recent advances in technology are beginning to identify biofluid molecular markers that may influence follicular development and oocyte quality. Accumulating evidence suggests that redox imbalance caused by abnormal energy metabolism and/or mitochondrial dysfunction is closely linked to the pathophysiology of age-related subfertility.

A systematic review identifying seminal plasma biomarkers and their predictive ability on IVF and ICSI outcomes

The diverse nature and high molecule concentration of seminal plasma (SP) makes this fluid a good potential source for a potential biomarker that could predict assisted reproductive technology (ART) outcomes. Currently, semen quality parameters cannot accurately predict ART outcomes. A systematic literature search was conducted to identify human SP biomarkers with potential predictive ability for the outcomes of IVF and intracytoplasmic sperm injection. Observational cohort and case-control studies describing the association between biomarkers in human SP and the outcome of infertile men attending for ART were included. Forty-three studies were selected, reporting on 89 potential SP biomarkers (grouped as oxidative stress, proteins glycoproteins, metabolites, immune system components, metals and trace elements and nucleic acids). The present review supports 32 molecules in SP as potentially relevant biomarkers for predicting ART outcomes; 23 molecules were reported once and nine molecules were reported in more than one study; IL-18 and TGF-β1-IL-18 ratio were confirmed in distinct studies. This review presents the most comprehensive overview of relevant SP biomarkers to predict ART outcomes to date, which is of clinical interest for infertility investigations and assisted reproduction; nevertheless, its potential is under-exploited. This review could serve as starting point for designing an all-encompassing study for biomarkers in SP and their predictive ability for ART outcomes, and for developing a non-invasive diagnostic tool.

A Pilot Prospective Study Evaluating the Effect of Curcuma-Based Herbal Food Supplement on the Outcome of In Vitro Fertilization in Patients Testing Positive for Four Immunological Biomarkers

Background and Objectives: Inflammation and oxidative stress have been described to reduce the chance for pregnancy instauration and maintenance. NOFLAMOX, a recently developed herbal preparation with recognized antioxidant and anti-inflammatory properties, can represent an interesting treatment to increase the chance of pregnancy, both physiological or after in vitro fertilization (IVF). The aim of this study was to assess NOFLAMOX's effect; a population with unexplained infertility was screened for the recently described IMMUNOX panel based on four immunological biomarkers with a prospective study approach. Materials and Methods: Patients with unexplained infertility and positive for at least one of the biomarkers of the IMMUNOX panel were included in this study and treated with NOFLAMOX for three months prior to an IVF cycle. Results: Eighty-six patients (n = 86) were screened with the IMMUNOX panel and the forty-seven (54.5%) found positive were included in this study. In more detail, 11 were positive for TNFα (23.4%), 18 (38.3%) for glycodelin (GLY), 29 (61.7%) for Total Oxidative Status (TOS), and 32 (68.1%) for Complement Activity Toxic Factor (CATF). After three months of treatment, a significant reduction in the number of IMMUNOX-positive patients was observable, with 26 patients who turned IMMUNOX-negative displaying a quantitative statistically significant variation of 100% (11/11), 38.9% (7/18), 65.5% (18/29), and 75% (24/32), for TNFα, glycodelin, TOS, and CATF, respectively. Followed in the subsequent IVF cycle, this NOFLAMOX-treated population showed a pregnancy rate of 42.3% compared to the 4.7% of the IMMUNOX-positive group of patients. Conclusions: Taken together, the results of this study suggest that NOFLAMOX could represent an interesting option for those patients with unexplained infertility of inflammatory/oxidative origin. Further studies are needed to confirm these results and explore possible strategies to restore fertility in women with immune-mediated sterility.

Effects of Melatonin, GM-CSF, IGF-1, and LIF in Culture Media on Embryonic Development: Potential Benefits of Individualization

The implantation of good-quality embryos to the receptive endometrium is essential for successful live birth through in vitro fertilization (IVF). The higher the quality of embryos, the higher the live birth rate per cycle, and so efforts have been made to obtain as many high-quality embryos as possible after fertilization. In addition to an effective controlled ovarian stimulation process to obtain high-quality embryos, the composition of the embryo culture medium in direct contact with embryos in vitro is also important. During embryonic development, under the control of female sex hormones, the fallopian tubes and endometrium create a microenvironment that supplies the nutrients and substances necessary for embryos at each stage. During this process, the development of the embryo is finely regulated by signaling molecules, such as growth factors and cytokines secreted from the epithelial cells of the fallopian tube and uterine endometrium. The development of embryo culture media has continued since the first successful human birth through IVF in 1978. However, there are still limitations to mimicking a microenvironment similar to the reproductive organs of women suitable for embryo development in vitro. Efforts have been made to overcome the harsh in vitro culture environment and obtain high-quality embryos by adding various supplements, such as antioxidants and growth factors, to the embryo culture medium. Recently, there has been an increase in the number of studies on the effect of supplementation in different clinical situations such as old age, recurrent implantation failure (RIF), and unexplained infertility; in addition, anticipation of the potential benefits from individuation is rising. This article reviews the effects of representative supplements in culture media on embryo development.

Comparison of In-House Microfluidic Device and Centrifuge-Based Method Efficacy in Sperm Preparation for Assisted Reproductive Technology

Background

Sperm DNA fragmentation can affect reproductive outcomes in assisted reproductive techniques (ART), and it is a concern in density gradient centrifugation (DGC). By contrast, microfluidic approaches allow the selection of highly motile sperm with low DNA fragmentation index (DFI). The purpose of current study, was to compare the efficacy of a microfluidic device designed in-house in comparison with DGC.

Methods

Nineteen healthy men with normal semen profiles were included in the study. Semen samples were individually aliquoted for three sperm preparation analyses (crude and processed with to either DGC or the microfluidic method). Sperm parameters of the samples were evaluated along with DNA fragmentation using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method.

Results

Sperm processed using the microfluidic method showed a significantly lower DFI than those obtained using DGC and in crude semen, with DFI of 1.1%, 3.5%, and 4.9%, respectively. Although the microfluidic method yielded significantly lower sperm concentrations than DGC, no significant differences were observed in total motility, progressive motility, curvilinear velocity, straight-line velocity, or normal morphology.

Conclusion

Using the in-house microfluidic device, sperm with lower DFI was effectively isolated when compared with DGC. The motility and normal morphology rates were comparable among the samples.

Role of Reactive Oxygen Species in Aging and Age-Related Diseases: A Review

Research on the role of reactive oxygen species (ROS) in the aging process has advanced significantly over the last two decades. In light of recent findings, ROS takes part in the aging process of cells along with contributing to various physiological signaling pathways. Antioxidants being cells' natural defense mechanism against ROS-mediated alteration, play an imperative role to maintain intracellular ROS homeostasis. Although the complete understanding of the ROS regulated aging process is yet to be fully comprehended, current insights into various sources of cellular ROS and their correlation with the aging process and age-related diseases are portrayed in this review. In addition, results on the effect of antioxidants on ROS homeostasis and the aging process as well as their advances in clinical trials are also discussed in detail. The future perspective in ROS-antioxidant dynamics on antiaging research is also marshaled to provide future directions for ROS-mediated antiaging research fields.

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.

Metabolic depletion of synaptosomal enzymes linked with neurotoxicity and ovarian dysfunction by phenolic antioxidants of Croton zambsicus leaves in rats exposed to chronic mixture of anthropogenic toxicant

A complex mixture of organic contaminants and metals is associated with neuron-fertility disorders and studies have demonstrated that phenolic antioxidants from herbal origin, possesses a strong protective potential. This study aimed to investigate the protection of phenolic croton zambesicus (C-ZAMB) leaves against neuro-ovarian damage in rats exposed to chronic mixture of anthropogenic toxicants (EOMABRSL). The animals were divided into five groups (n = 10): Group I was given 0.5 ml of distilled water only; Group II received 0.5 ml of EOMABRSL for 98 days; Group III received 0.5 ml of EOMABRSL for 70 days and withdrew for 28 days; Group IV received 0.5 ml of EOMABRSL for 70 days +400 mg/kg phenolic C-ZAMB for 28 days; Group V received 400 mg/kg C-ZAMB only for 28 days via oral route. Both non-withdrawal and withdrawal EOMABRSL-exposed animals exhibited neuro-ovarian impairment by up-regulating neuronal 51 eco-nucleotidase (51ENT), acetylcholinesterase (AChE), butrylcholinesterase (BuChE), synaptosomal monoamine oxidase-A (MAO-A) with altered cerebral antioxidants. Similarly, exposure to EOMABRSL for 98 and 70 days caused ovarian injury by amplifying the activity of 51ENT with corresponding decline of fertility index, lactate dehydrogenase (LDH) and Δ5 17β-hydroxyl steroid dehydrogenase (Δ517β-HSD). EOMABRSL intoxication also increased the neuro-ovarian MDA content with reduced numbers of neonates. Phenolic antioxidants from C-ZAMB leaves identified by High Pressure Liquid Chromatography (HPLC) ameliorated the chronic EOMABRSL intoxication. The treatment also prevented ovarian lesions by depleting MDA content and improved antioxidant status. Thus, confirming its neuro-ovarian protection.

Melatonin and its mechanism of action in the female reproductive system and related malignancies

Melatonin (N-acetyl-5-methoxytryptamine), the main product of pineal gland in vertebrates, is well known for its multifunctional role which has great influences on the reproductive system. Recent studies documented that melatonin is a powerful free radical scavenger that affects the reproductive system function and female infertility by MT1 and MT2 receptors. Furthermore, cancer researches indicate the influence of melatonin on the modulation of tumor cell signaling pathways resulting in growth inhibitor of the both in vivo/in vitro models. Cancer adjuvant therapy can also benefit from melatonin through therapeutic impact and decreasing the side effects of radiation and chemotherapy. This article reviews the scientific evidence about the influence of melatonin and its mechanism of action on the fertility potential, physiological alteration, and anticancer efficacy, during experimental and clinical studies.

Are women with small endometriomas who undergo intracytoplasmic sperm injection at an elevated risk for adverse pregnancy, obstetric, and neonatal outcomes?

Objective

The aim of the study was to investigate pregnancy, obstetric, and neonatal outcomes in women with small (<4 cm) unilateral endometriomas.

Methods

This retrospective study included 177 patients: 91 patients with small endometriomas and 86 controls with unexplained or tubal factor infertility who were treated at the Süleymaniye Gynecology and Maternity Training and Research Hospital Infertility Unit between January 2010 and July 2015. The groups were matched with regards to demographic characteristics such as age, body mass index, and infertility duration. All of the women in this study conceived via intracytoplasmic sperm injection. We compared pregnancy, obstetric, and neonatal outcomes between these groups.

Results

Women with endometriomas had a higher biochemical pregnancy rate, but lower clinical pregnancy and live birth rates than women with unexplained and tubal factor infertility (p<0.05 for all). However no significant differences were found in terms of obstetric and neonatal complications between the two groups (p>0.05 for all).

Conclusion

In this study, we found that women with endometriomas less than 4 cm were more prone to early pregnancy complications. We also showed that this group did not have any increased risks of late pregnancy, obstetric, and neonatal complications.

Oxidative stress and male infertility

BACKGROUND

Between 30% and 80% of patients with male infertility produce excessive reactive oxygen species (ROS) in their ejaculate even though the cause of male infertility is unexplained in approximately half of cases. The strong connection between oxidative stress (OS) and male infertility has led recent investigators to propose the term "Male Oxidative Stress Infertility (MOSI)" to describe OS-associated male infertility.

METHODS

We searched the PubMed database for original and review articles to survey the effects of OS on male infertility, and then verified the effects and treatments.

MAIN FINDINGS

Seminal plasma contains many antioxidants that protect sperm from ROS, because low amounts of ROS are required in the physiological fertilization process. The production of excessive ROS causes OS which can lower fertility through lipid peroxidation, sperm DNA damage, and apoptosis. Several assays are available for evaluating OS, including the MiOXSYS® analyzer to measure oxidation-reduction potential. Several measures should be considered for minimizing OS and improving clinical outcomes.

CONCLUSION

Accurately diagnosing patients with MOSI and identifying highly sensitive biomarkers through proteomics technology is vital for better clinical outcomes.

Urinary oxidative stress biomarker levels and reproductive outcomes among couples undergoing fertility treatments

STUDY QUESTION

Are urinary levels of oxidative stress biomarkers associated with reproductive outcome success following fertility treatments?

SUMMARY ANSWER

Levels of oxidative stress in the middle tertile for women are associated with the highest levels of reproductive success while no associations were noted for men.

WHAT IS KNOWN ALREADY

Oxidative stress may contribute to adverse fertility outcomes in the general population, but findings from couples undergoing fertility treatments are sparse.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 481 women and 249 of their male partners undergoing fertility treatments from 2007 to 2015, from the Environment and Reproductive Health (EARTH) study in Boston, MA.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One urine sample per participant was collected at each cycle and analysed for two oxidative stress markers: 8-isoprostane-PGF2α (8-iso-PGF2α) and 8-isoprostane-PGF2α metabolite (F2-isoP-M). Reproductive outcomes were abstracted from medical records and included the fertilization rate, for IVF (oocytes fertilized/mature oocytes retrieved), and rates of implantation, clinical pregnancy and live birth, for both IVF and IUI. Cluster-weighted generalized estimating equations were used to analyse adjusted associations between exposure tertiles and outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Levels of F2-isoP-M in the middle tertile were associated with the most success among women. Women in the upper tertile of F2-isoP-M had an adjusted mean live birth rate after IVF and IUI of 23% (95% CI: 17, 29) compared to 38% (95% CI: 31, 45) for women in the middle tertile and 27% (95% CI: 21, 34) in the lower tertile. The fertilization rate during IVF was higher for women with 8-iso-PGF2α in the middle tertile (0.77 [95% CI: 0.73, 0.80]) compared to women in the lower (0.69 [95% CI: 0.64, 0.73]) or upper tertiles (0.66 [95% CI: 0.61, 0.71]). No significant associations were found for other measured outcomes with 8-iso-PGF2α, or between any oxidative stress biomarker in men and reproductive outcomes in their partners.

LIMITATIONS, REASONS FOR CAUTION

Isoprostanes are short-lived biomarkers and this study may not have captured the most relevant window of susceptibility for oxidative stress on the outcomes of interest. Findings from this study may not be generalizable to couples attempting conception without fertility assistance.

WIDER IMPLICATIONS OF THE FINDINGS

This study suggests that a non-linear association may exist between oxidative stress and reproductive outcomes in a population undergoing fertility treatment, a finding not previously identified in the literature. Oxidative stress may represent the mechanism through which environmental chemicals are associated with adverse reproductive outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the Intramural Research Program of the National Institutes of Environmental Health Sciences (NIEHS) (ZIA ES103314) and by NIEHS grants R01ES022955, R01ES009718 and R01ES00002. There are no competing interests to report.

TRIAL REGISTRATION NUMBER

N/A.

Reactive oxygen species in reproduction: harmful, essential or both?

The process of embryonic development is crucial and radically influences preimplantation embryo competence. It involves oocyte maturation, fertilization, cell division and blastulation and is characterized by different key phases that have major influences on embryo quality. Each stage of the process of preimplantation embryonic development is led by important signalling pathways that include very many regulatory molecules, such as primary and secondary messengers. Many studies, both in vivo and in vitro, have shown the importance of the contribution of reactive oxygen species (ROS) as important second messengers in embryo development. ROS may originate from embryo metabolism and/or oocyte/embryo surroundings, and their effect on embryonic development is highly variable, depending on the needs of the embryo at each stage of development and on their environment (in vivo or under in vitro culture conditions). Other studies have also shown the deleterious effects of ROS in embryo development, when cellular tissue production overwhelms antioxidant production, leading to oxidative stress. This stress is known to be the cause of many cellular alterations, such as protein, lipid, and DNA damage. Considering that the same ROS level can have a deleterious effect on the fertilizing oocyte or embryo at certain stages, and a positive effect at another stage of the development process, further studies need to be carried out to determine the rate of ROS that benefits the embryo and from what rate it starts to be harmful, this measured at each key phase of embryonic development.

Human prostasomes an extracellular vesicle - Biomarkers for male infertility and prostrate cancer: The journey from identification to current knowledge

Extracellular vesicles (EVs) are gaining attention among the cell biologists and researchers over the last two decades. Prostasomes are considered to be (Evs) secreted by prostate epithelial cells into the semen during emission or ejaculation. Prostasomes contain various proteins required for immune regulation namely, amino and dipeptidyl peptidase; endopeptidase (neutral); decay accelerating factor; angiotensin-converting enzyme. Sperm cells need a few prerequisites in order to fertilize the egg. The role of prostasomes in enhancing the male fertility was reviewed extensively throughout the manuscript. Also, prostasomes have an immunosuppressive, immunomodulatory, antibacterial role in the female reproductive tract, and in some cases they can be used as immunocontraceptive agent to regulate the fertility status. This review will give insights to many active researchers in the field of prostasomal research and male infertility/fertility research. This review will open many unanswered mechanisms of prostasomes with respect to structure-function analysis, fatty acids patterns in diagnosis as well as prognosis of male infertility/fertility. More scientific reports are in need to support the mechanism of prostasomes and its role in immunomodulation. The development of prostasomes as a biomarker for the prostate cancer is still miserable with a lot of controversial results by various researchers.

The sensitivity of the DNA damage checkpoint prevents oocyte maturation in endometriosis

Mouse oocytes respond to DNA damage by arresting in meiosis I through activity of the Spindle Assembly Checkpoint (SAC) and DNA Damage Response (DDR) pathways. It is currently not known if DNA damage is the primary trigger for arrest, or if the pathway is sensitive to levels of DNA damage experienced physiologically. Here, using follicular fluid from patients with the disease endometriosis, which affects 10% of women and is associated with reduced fertility, we find raised levels of Reactive Oxygen Species (ROS), which generate DNA damage and turn on the DDR-SAC pathway. Only follicular fluid from patients with endometriosis, and not controls, produced ROS and damaged DNA in the oocyte. This activated ATM kinase, leading to SAC mediated metaphase I arrest. Completion of meiosis I could be restored by ROS scavengers, showing this is the primary trigger for arrest and offering a novel clinical therapeutic treatment. This study establishes a clinical relevance to the DDR induced SAC in oocytes. It helps explain how oocytes respond to a highly prevalent human disease and the reduced fertility associated with endometriosis.