Redox profiling of preovulatory follicular fluid in the donkey is species-specific, and contributes to modulate sperm function

The follicular fluid (FF) is crucial for providing oocytes with an ideal environment that promotes their development and maturation. Not only does this fluid supply nutrients and hormones, but also other components that protect both follicular cells and the oocyte itself from potential harmful factors, such as those inducing oxidative stress (OS). The FF has also been suggested to have beneficial effects on sperm when they reach the oviduct. The objectives of this study were to describe the presence and activity levels of redox biomarkers in the preovulatory follicular fluid (PFF), and to analyze the impact of PFF on the motility, viability and reactive oxygen species (ROS) levels of donkey sperm. For this purpose, ten PFF samples obtained from Catalan jennies and nine ejaculates collected from Catalan donkeys were used. Redox biomarkers -including enzymatic and non-enzymatic antioxidants, and oxidative biomarkers- were analyzed in jennies' PFF. After collection, each semen sample was split into two aliquots of equal volume. The two aliquots were centrifuged to remove the seminal plasma; one pellet was resuspended in Tris Buffered Medium (TBM), and the other was resuspended in TBM supplemented with 20% PFF. Motility parameters (CASA) and other semen quality biomarkers (flow cytometry) were assessed after 0, 60 and 120 min of incubation at 38 °C. Exposure of donkey sperm to PFF reduced intracellular ROS levels and helped maintain sperm motility and viability. These findings suggest that, in the oviduct, the PFF components protect donkey sperm from oxidative stress. Furthermore, knowing better the composition of donkey PFF in terms of antioxidant biomarkers may be used to improve the formulation of media for oocyte maturation and fertilization in this and other species.

A Comparative Analysis of the Antioxidant Profiles Generated by the RoXstaTM System for Diverse Biological Fluids Highlights the Powerful Protective Role of Human Seminal Plasma

(1) Background: The RoXstaTM system has been developed as a rapid, effective means of profiling different types of antioxidant activity. The purpose of this study was to examine its performance utilizing a diverse array of biological fluids including semen, blood plasma, serum, urine, saliva, follicular fluid and plant extracts. (2) Methods: The RoXstaTM system was used to assess the ability of different fluids to suppress free radical formation as well as scavenge a variety of toxic oxygen metabolites including free radicals and both hydrogen and organic peroxides. (3) Results: Human semen was shown to have significantly (p < 0.001) more peroxide scavenging power than any other fluid tested (10-14 mM vitamin C equivalent compared with 1-2 mM for blood serum or plasma), while urine was particularly effective in scavenging free radicals and preventing free radical formation (p < 0.001). The powerful antioxidant properties of human semen were shown to reside within the seminal plasma (SP) fraction, rather than the spermatozoa, and to be resistant to snap freezing in liquid nitrogen. Moreover, comparative studies demonstrated that human SP exhibited significantly (p < 0.001) higher levels of antioxidant potential than any other species examined (stallion, bull, dog) and that this intense activity reflected the relative vulnerability of human spermatozoa to peroxide attack. (4) Conclusions: The RoXstaTM system provides valuable information on the antioxidant profile of complex biological fluids, supporting its diagnostic role in conditions associated with oxidative stress. Based on the results secured in this study, human semen is identified as a particularly rich source of antioxidants capable of scavenging both hydrogen and organic peroxides, in keeping with the high susceptibility of human spermatozoa to peroxide-mediated damage.

A Paper-Based Assay for the Determination of Total Antioxidant Capacity in Human Serum Samples

Determining the total antioxidant capacity (TAC) of biological samples is a valuable approach to measuring health status under oxidative stress conditions, such as infertility and type 2 diabetes. The Trolox equivalent antioxidant capacity (TEAC) assay is the most common approach to evaluating TAC in biological matrices. This assay is typically performed in clinical settings on a microtiter plate using a plate reader. However, the instrumentation and expertise requirements, and the resulting delay in the reporting of assay outcomes, make solution-based TEAC assays impractical for point-of-care or at-home testing, where individuals may want to monitor their health status during treatment. This work introduces the first microfluidic paper-based analytical device (µPAD) that measures TAC in human serum using TEAC assay chemistry. TAC was determined through a colorimetric image analysis of the degree of decolorization of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cations (ABTS●+) by serum antioxidants. The µPAD showed a linear response to Trolox, ranging from 0.44 to 2.4 mM, (r  =  0.999). The performance of paper-based TEAC assays was validated through direct comparison to solution-based TEAC assays. There was a 0.04 mM difference in TAC values between the two platforms, well within one standard deviation of a standard solution-based assay conducted on an aliquot of the same serum sample (±0.25 mM). The µPAD had a limit of detection (LOD) of 0.20 mM, well below the TAC of normal human serum. The results suggest that the proposed device can be used for biological TAC determination and expands the field of TAC analysis in point-of-care health monitoring.

Astaxanthin treatment ameliorates ER stress in polycystic ovary syndrome patients: a randomized clinical trial

Astaxanthin (ASX), as a natural carotenoid compound, exists in various types of seafood and microorganisms. It has several possible beneficial therapeutic effects for patients with polycystic ovary syndrome (PCOS). Patients with PCOS also suffer from endoplasmic reticulum (ER) stress. In the present work, it was hypothesized that ER stress could be improved by ASX in PCOS patients. Granulosa cells (GCs) were obtained from 58 PCOS patients. The patients were classified into ASX treatment (receiving 12 mg/day for 60 days) and placebo groups. The expression levels of ER stress pathway genes and proteins were explored using Western blotting and quantitative polymerase chain reaction. To assess oxidative stress markers, follicular fluid (FF) was gained from all patients. The Student's t test was used to perform statistical analysis. After the intervention, ASX led to a considerable reduction in the expression levels of 78-kDa glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), and X-box-binding protein 1 compared to the placebo group, though the reduction in the messenger RNA (mRNA) expression level of activating transcription factor 6 was not statistically significant. However, ASX significantly increased the ATF4 expression level. GRP78 and CHOP protein levels represented a considerable decrease in the treatment group after the intervention. In addition, a statistically significant increase was found in the FF level of total antioxidant capacity in the treatment group. Based on clinical outcomes, no significant differences were found between the groups in terms of the oocyte number, fertilization rate, and fertility rate, but the ASX group had higher rates of high-quality oocytes, high-quality embryo, and oocyte maturity compared to the placebo group. Our findings demonstrated that ER stress in the GCs of PCOS patients could be modulated by ASX by changing the expression of genes and proteins included in the unfolding protein response.Trial registration This study was retrospectively registered on the Iranian Registry of Clinical Trials website ( www.irct.ir ; IRCT-ID: IRCT20201029049183N, 2020-11-27).

Seasonal variations in the metabolomic profile of the ovarian follicle components in Italian Mediterranean Buffaloes

The aim of this work was to evaluate the seasonal effect on the metabolomic profile of the ovarian follicle in Italian Mediterranean buffalo to unravel the causes of the reduced competence during the non-breeding season (NBS). Samples of follicular fluid, follicular cells, cumulus cells and oocytes were collected from abattoir-derived ovaries during breeding season (BS) and NBS and analyzed by 1H Nuclear Magnetic Resonance. The Orthogonal Projections to Latent Structures of the Discriminant Analysis showed clear separation into seasonal classes and Variable Importance in Projection method identified differentially abundant metabolites between seasons. Seasonal differences were recorded in metabolite content in all analyzed components suggesting that the decreased oocyte competence during NBS may be linked to alteration of several metabolic pathways. The pathway enrichment analysis revealed that differences in the metabolites between the seasons were linked to glutathione, energy generating and amino acid metabolism and phospholipid biosynthesis. The current work allows the identification of potential positive competence markers in the follicular fluid as glutathione, glutamate, lactate and choline, and negative markers like leucine, isoleucine and β-hydroxybutyrate. These results form a major basis to develop potential strategies to optimize the follicular environment and the IVM medium to improve the competence of oocytes during the NBS.

Melatonin levels and microRNA (miRNA) relative expression profile in the follicular ambient microenvironment in patients undergoing in vitro fertilization process

PURPOSE

Intrafollicular fluid (IFF) melatonin plays a decisive role in maintaining granulosa cells' DNA integrity and protects them against apoptosis. It reduces oxidative stress and improves the oocyte quality with a higher fertilization rate.

METHOD

This prospective study investigated the antioxidant property of IFF melatonin and its impact on IVF outcome parameters. We also explored the relative expression of five microRNAs (miR-663b, miR-320a, miR-766-3p, miR-132-3p, miR-16-5p) and levels of cell-free DNA (cfDNA) by real-time PCR in unexplained infertile patients. We collected 425 follicular fluid (FF) samples containing mature oocytes from 295 patients undergoing IVF.

RESULTS

Patients were subgrouped based on IFF melatonin concentration (group A ≤ 30 pg/mL, group B > 70 to ≤ 110 pg/mL, group C > 111 to ≤ 385 pg/mL). Our results showed that patients with ≤ 30 pg/mL IFF melatonin levels have significantly higher oxidative stress markers, cfDNA levels, and lower relative expression of miR-663b, miR-320a, miR-766-3p, miR-132-3p, and miR-16-5p compared to other subgroups (p < 0.001). Similarly, they have a low fertilization rate and a reduced number of high-quality day 3 embryos.

CONCLUSION

Findings suggest that the therapeutic use of melatonin produces a considerable rise in the number of mature oocytes retrieved, fertilization rate, and good-quality embryo selection. Furthermore, miRNA signature enhances the quality of embryo selection, thus, may allow us to classify them as non-invasive biomarkers to identify good-quality embryos.

Growth hormone alleviates oxidative stress and improves oocyte quality in Chinese women with polycystic ovary syndrome: a randomized controlled trial

Oxidative stress (OS) is associated with poor oocyte quality and in vitro fertilization and embryo transfer (IVF-ET) outcomes for patients with polycystic ovary syndrome (PCOS). Growth hormone (GH) can function to reduce OS in some types of cells. Therefore, this prospective randomized study investigated whether GH can significantly improve OS and oocyte quality in women with PCOS. This study enrolled 109 and 50 patients with and without PCOS (controls), respectively. The patients with PCOS were randomly assigned to receive treatment with GH (PCOS-T) or not (PCOS-C). The primary outcome included markers of OS in serum and FF, and secondary outcomes were mitochondrial function in granulosa cells (GCs) and IVF-ET outcomes. The PCOS groups showed higher basal serum total oxidant status (TOS) and OS index (OSI) levels. The follicle fluid (FF) TOS and OSI and GC apoptosis rate were significantly higher, whereas the GC mitochondrial membrane potential (MMP) was significantly lower in the PCOS-C group than in the PCOS-T and non-PCOS control groups (P < 0.05). Significantly more oocytes were fertilised and cleavage stage embryos were produced in the PCOS-T group than in the PCOS-C group (P < 0.05). GH also improved the rates of implantation and clinical pregnancy, but not significantly (P > 0.05). This study showed that GH alleviated the TOS and OSI level in FF and improved GC mitochondrial dysfunction and oocyte quality in patients with PCOS.

Clinical Trial Registration Number: This project was prospectively registered on the Chinese Clinical Trial Registry on October 20, 2018. (ChiCTR1800019437) (https://www.chictr.org.cn/edit.aspx?pid=28663&htm=4).

Growth hormone alleviates oxidative stress and improves the IVF outcomes of poor ovarian responders: a randomized controlled trial

BACKGROUND

Oxidative stress (OS), defined as an imbalance between excessive reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) production and antioxidant insufficiency, has been suggested to be involved in the pathogenesis of poor ovarian response (POR). Growth hormone (GH) can reduce OS in some cell types. This study investigated whether GH can improve OS and the in vitro fertilization and embryo transfer (IVF-ET) outcomes of poor ovarian responders.

METHODS

This study enrolled 105 patients with POR and 58 patients without POR (controls) who were diagnosed according to the Bologna criteria and underwent conventional IVF-ET. Poor ovarian responders were randomly assigned to two groups: the POR-GH group, which received pretreatment with GH 4 IU/d on day 2 of the previous menstrual cycle before IVF until the trigger day, and the POR-C group, which received no pretreatment. OS markers in follicular fluid (FF), ROS levels in granulosa cells (GCs), and the IVF outcomes of the groups were compared.

RESULTS

Endometrial thickness on trigger day, the number of cleaved embryos, the number of higher-quality embryos, and the rates of embryo formation, higher-quality embryo formation, implantation and clinical pregnancy were significantly increased in the POR-GH group compared with the POR-C group (P < 0.05). Moreover, compared to those in the non-POR group, FF malondialdehyde (MDA), total oxidant status (TOS), oxidative stress index (OSI) and ROS levels in GCs were significantly higher, whereas superoxide dismutase (SOD) and the total antioxidant capacity (TAC) were significantly lower in the POR-C group (P < 0.05). Furthermore, compared with those in the POR-C group, the FF TAC was significantly increased in the POR-GH group, and TOS, OSI and intracellular ROS levels were significantly reduced (P < 0.05).

CONCLUSIONS

Pretreatment with GH alleviates OS and improves oocyte quality and IVF outcomes of poor ovarian responders.

TRIAL REGISTRATION

Chinese Clinical Trial Registry. ChiCTR1900021269 . Registered 8 February 2019, http://www.chictr.org.cn/edit.aspx?pid=35837&htm=4 .

Oxidative stress biomarkers in endometrial secretions: A comparison between successful and unsuccessful in vitro fertilization cycles

A potential role of oxidative stress has been implicated in the outcome of various steps of assisted reproductive technology (ART). In a prospective cohort study, a total of 100 patients undergoing IVF/ICSI procedure due to male factor infertility were recruited based on the inclusion criteria. In all patients, 1-2ml of endometrial secretions was aspirated prior to embryo transfer. The oxidative stress markers in endometrial secretions, including superoxide dismutase (SOD), catalase (CAT) activities, lipid peroxidation (LPO), total thiol groups (TTG), and total antioxidant power (TAP) were investigated and compared among study groups including term pregnancy, failed IVF cycle, and miscarriage. P<0.05 was considered statistically different. Of the 100 patients, 28 cases (28%) resulted in ongoing pregnancy (biochemical pregnancy followed by clinical pregnancy), 11 cases (11%) resulted in miscarriage, and 61 cases (61%), resulted in failed IVF cycle. SOD, LPO, CAT, and TAP levels in the endometrial secretions of the three groups were statistically different (P-value <0.01, <0.001, <0.001, and <0.001, respectively). TTG levels in endometrial secretion of three groups were not statistically different (P-value=0.837). Our results indicated that higher levels of antioxidants such as SOD, CAT, or TAP, and lower levels of oxidative stress markers such as LPO in the endometrial secretions were associated with successful IVF outcome.

Follicular fluid total antioxidant capacity levels in PCOS

In this study, our aim was to assess total antioxidant capacity (TAC) levels in follicular fluid (FF) and their relationship to clinical pregnancy rates in PCOS patients undergoing assisted reproduction (ART). Twenty-two women with polycystic ovary syndrome (PCOS) (Group 1) and 41 women without PCOS (Group 2) were included in this study. Clinical and laboratory parameters and FF TAC levels were investigated. No statistically significant differences were found between the groups with regard to age and baseline parameters. Although we could not demonstrate a significant difference in FF TAC levels between the two groups (p=0.469), there was a significant positive correlation between FF TAC and clinical pregnancy rates, BMI, and the duration of infertility for the entire group (r=0.254, p=0.048; r=0.312, p=0.013; r=0.259, p=0.040; respectively). Owing to the correlation between FF TAC and the clinical pregnancy rates, further studies evaluating the impact of FF TAC levels on ART outcomes in patients with PCOS and other etiologies of infertility are needed.

Relationship between oxidative stress and clinical pregnancy in assisted reproductive technology treatment cycles

Purpose

To examine the relationship between serum total oxidant (TOS) and antioxidant (TAS) levels and clinical pregnancy in assisted reproductive technology (ART) cycles.

Methods

Prior to and after oocyte pick-up (OPU) and embryo transfer (ET), blood samples were collected from gynecologically normal females (n = 70) who were enrolled for ART solely due to male factor infertility. TAS, TOS levels and oxidative stress indexes (OSI: TOS/TAS) in four phases of treatment cycle (pre and post OPU and ET) between clinically pregnant and non-pregnant patients were compared. Critical cut-off values of significantly different TAS, TOS levels and OSIes for clinical pregnancy were established.

Results

The TAS levels in patients with clinical pregnancy were significantly higher in all of the four phases of the cycle. Post-OPU and pre-ET TOS levels were significantly higher in clinically pregnant patients. According to OSIes; only the pre-OPU OSI was significantly lower in clinically pregnant patients compared with non-pregnant ones. Moreover, the highest area under the ROC curve (AUC) from the seven different significant measurements [1) pre-OPU OSI, 2) pre-OPU TAS, 3) post-OPU TAS, 4) pre-ET TAS, 5) post-ET TAS, 6) post-OPU TOS, 7) pre-ET TOS] was related to pre-OPU OSI.

Conclusions

In ART cycles, women with a higher total antioxidant status prior to and after OPU and prior to and after ET have an increased probability of clinical pregnancy. Additionally; OSI before OPU was one of the most important determinants for clinical pregnancy, so the oxidant and antioxidant balance is as important as the antioxidant concentration alone.

Age related changes in mitochondrial function and new approaches to study redox regulation in mammalian oocytes in response to age or maturation conditions

Mammalian oocytes are long-lived cells in the human body. They initiate meiosis already in the embryonic ovary, arrest meiotically for long periods in dictyate stage, and resume meiosis only after extensive growth and a surge of luteinizing hormone which mediates signaling events that overcome meiotic arrest. Few mitochondria are initially present in the primordial germ cells while there are mitogenesis and structural and functional differentiation and stage-specific formation of functionally diverse domains of mitochondria during oogenesis. Mitochondria are most prominent cell organelles in oocytes and their activities appear essential for normal spindle formation and chromosome segregation, and they are one of the most important maternal contributions to early embryogenesis. Dysfunctional mitochondria are discussed as major factor in predisposition to chromosomal nondisjunction during first and second meiotic division and mitotic errors in embryos, and in reduced quality and developmental potential of aged oocytes and embryos. Several lines of evidence suggest that damage by oxidative stress/reactive oxygen species in dependence of age, altered antioxidative defence and/or altered environment and bi-directional signaling between oocyte and the somatic cells in the follicle contribute to reduced quality of oocytes and blocked or aberrant development of embryos after fertilization. The review provides an overview of mitogenesis during oogenesis and some recent data on oxidative defence systems in mammalian oocytes, and on age-related changes as well as novel approaches to study redox regulation in mitochondria and ooplasm. The latter may provide new insights into age-, environment- and cryopreservation-induced stress and mitochondrial dysfunction in oocytes and embryos.