Comparison of antagonist mild and long agonist protocols in terms of follicular fluid total antioxidant capacity

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.

The role of follicular anti-Mullerian hormone in women undergoing IVF/ICSI with regard to size, oocyte presence, sociodemographic parameters, treatment variables, and other hormones and vitamins

AIMS

The aim of this study was to evaluate the relationship between follicular anti-Mullerian hormone (fAMH) regarding follicle size, the presence of an oocyte, sociodemographic parameters, and other hormones and vitamins in follicular fluid.

MATERIALS AND METHODS

This prospective exploratory cohort study included 376 follicles from 61 women undergoing IVF/ICSI cycles. The size of each follicle was measured individually, and they were divided into a large and a small group according to their size. The presence of oocytes was detected on the day of oocyte retrieval. Sociodemographic factors were documented during the course of preliminary testing. Then, other parameters of patients' serum and follicular fluid were measured.

RESULTS

Small follicles contained a significantly higher concentration of fAMH than large ones did. We showed that the presence of an oocyte in a follicle is associated with a significantly higher fAMH level than in those without one (p < .001). There exists a significant but weak correlation between fAMH and the sociodemographic parameter of patients' age (r = -0.11, p < .001). We did not find a correlation with the patients' BMI (r = 0.03, p < .006). We also investigated the connections between fAMH and other parameters, such as vitamin D (r = -0.13, p < .001), LH (r = 0.35, p < .001)), and progesterone (r = -0.21, p < .001) in follicular fluid.

CONCLUSIONS

This knowledge can be useful for the future development of reproductive medicine. Our results can provide an important building block for this matter.

Clinical and Molecular Effects of GnRH Agonist and Antagonist on The Cumulus Cells in The In Vitro Fertilization Cycle

Background:

Gonadotropin-releasing hormone (GnRH) analogues have been extensively utilized in the ovarian stimulation cycle for suppression of endogenous rapid enhancement of luteinizing hormone (LH surge). Exclusive properties and functional mechanisms of GnRH analogues in in vitro fertilization (IVF) cycles are clearly described. This study was performed to evaluate clinical and molecular impacts of the GnRH agonist and antagonist protocols in IVF cycles. For This purpose, gene expression of cumulus cells (CCs) as well as clinical and embryological parameters were evaluated and compared between two groups (GnRH agonistand antagonist) during the IVF cycle.

Materials and Methods:

Twenty-one infertile individuals were enrolled in this study. Subjects were selected from two groups of GnRH agonist(n=10) treated patients and GnRH antagonist (n=11) treated individuals. The defined clinical embryological parameters were compared between the two groups. Expression of BAX, BCL-2, SURVIVIN, ALCAM, and VCAN genes were assessed in the CCs of the participants using the real-time polymerase chain reaction (PCR) technique.

Results:

The mean number of cumulus oocyte complex (COC), percentage of metaphase II (MII) oocytes, grade A embryo and clinical parameters did not show noticeable differences between the two groups. BAX gene expression in the CCs of the group treated with GnRH agonist was remarkably higher than those received GnRH antagonist treatment (P<0.001). The mRNA expression of BCL-2 and ALCM genes were considerably greater in the CCs of patients who underwent antagonist protocol in comparison to the group that received agonist protocol (P<0.001).

Conclusion:

Despite no considerable difference in the oocyte quality, embryo development, and clinical outcomes between the group treated with GnRH agonist and the one treated with antagonist protocol, the GnRH antagonist protocol was slightly more favorable. However, further clinical studies using molecular assessments are required to elucidate this controversial subject.

Mitochondria-targeted therapy rescues development and quality of embryos derived from oocytes matured under oxidative stress conditions: a bovine in vitro model

STUDY QUESTION

Can we use a mitochondrial-targeted antioxidant (Mitoquinone) during in vitro embryo culture to rescue developmental competence of oocytes matured under lipotoxic conditions, exhibiting mitochondrial dysfunction and oxidative stress?

SUMMARY ANSWER

Supplementation of embryo culture media with Mitoquinone reduced oxidative stress and prevented mitochondrial uncoupling in embryos derived from metabolically compromised oocytes in vitro, leading to higher blastocyst rates and lower blastomeric apoptosis.

WHAT IS KNOWN ALREADY

Maternal metabolic disorders, such as obesity and type-II diabetes are associated with hyperlipidemia and elevated free fatty acid (FFA) concentrations in the ovarian follicular fluid (FF). Oocyte maturation under these lipotoxic conditions results in increased oxidative stress levels, mitochondrial dysfunction, reduced developmental competence and disappointing IVF results.

STUDY DESIGN, SIZE, DURATION

A well-described bovine oocyte IVM model was used, where a pathophysiologically relevant elevated FF concentrations of palmitic acid (PA; 150 μM or 300 μM) were added to induce oxidative stress. After fertilization (Day 0, D0), zygotes were in vitro cultured (IVC, from D1 to D8) in standard fatty acid-free media in the presence or absence of Mitoquinone or its carrier triphenyl-phosphonium.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Embryo cleavage and fragmentation (D2) and blastocyst rates (D8) were recorded. Mitochondrial activity and oxidative stress in cleaved embryos at D2 were determined using specific fluorogenic probes and confocal microscopy. D8 blastocysts were used to (i) examine the expression of marker genes related to mitochondrial unfolded protein responses (UPRmt; HSPD1 and HSPE1), mitochondrial biogenesis (TFAM), endoplasmic reticulum (ER) UPR (ATF4, ATF6 and BiP) and oxidative stress (CAT, GPX1 and SOD2) using real time RT-PCR; (ii) determine cell differentiation and apoptosis using CDX-2 and cleaved caspase-3 immunostaining; and (iii) measure mtDNA copy numbers. This was tested in a series of experiments with at least three independent replicates for each, using a total of 2525 oocytes. Differences were considered significant if a P value was <0.05 after Bonferroni correction.

MAIN RESULTS AND THE ROLE OF CHANCE

Exposure to PA during IVM followed by culture under control conditions resulted in a significant increase in oxidative stress in embryos at D2. This was associated with a significant reduction in mitochondrial inner membrane potential (uncoupling) compared with solvent control (P < 0.05). The magnitude of these effects was PA-concentration dependent. Consequently, development to the blastocysts stage was significantly hampered. Surviving blastocysts exhibited high apoptotic cell indices and upregulated mRNA expression indicating persistent oxidative stress, mitochondrial and ER UPRs. In contrast, supplementation of PA-derived zygotes with Mitoquinone during IVC (i) prevented mitochondrial uncoupling and alleviated oxidative stress at D2; and (ii) rescued blastocyst quality; normalized oxidative stress and UPR related genes and apoptotic cell indices (P > 0.01 compared with solvent control). Mitoquinone also improved blastocyst rate in PA-exposed groups, an effect that was dependent on PA concentration.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This is a fundamental study performed using a bovine in vitro model using PA-induced lipotoxicity during oocyte maturation. PA is the most predominant FFA in the FF that is known to induce lipotoxicity; however, in vivo maturation in patients suffering from maternal metabolic disorders involve more factors that cannot be represented in one model. Nevertheless, focusing on the carryover oxidative stress as a known key factor affecting developmental competence, and considering the novel beneficial rescuing effects of Mitoquinone shown here, we believe this model is of high biological relevance.

WIDER IMPLICATIONS OF THE FINDINGS

Human oocytes collected for IVF treatments from patients with maternal metabolic disorders are vulnerable to lipotoxicity and oxidative stress during in vivo maturation. The results shown here suggest that mitochondrial targeted therapy, such as using Mitoquinone, during IVC may rescue the developmental competence and quality of these compromised oocytes. After further clinical trials, this may be a valuable approach to increase IVF success rates for infertile patients experiencing metabolic disorders.

STUDY FUNDING/COMPETING INTEREST(S)

This study was financially supported by a BOF/KP grant number 34399, from the University of Antwerp, Belgium. W.F.A.M. was supported by a postdoctoral fellowship from the Research Foundation-Flanders (FWO), grant number 12I1417N, Antwerp, Belgium. The Leica SP 8 confocal microscope used in this study was funded by the Hercules Foundation of the Flemish Government (Hercules grant AUHA.15.12). All authors have no financial or non-financial competing interests to declare.

Oxidative balance in follicular fluid of ART patients of advanced maternal age and blastocyst formation

OBJECTIVE

To evaluate the follicular fluid oxidative balance of infertile patients of advanced-maternal-age and the correlation between oxidative imbalance in the follicular fluid and the embryological outcomes.

METHODS

Follicular fluid (FF) from infertile patients of advanced-maternal-age undergoing ART treatments were collected and frozen in cryovials at -86°C until further use, and analyzed at the Biochemistry and Nutrition Institute of San Marcos University. As controls, we used FF from oocyte donors. The FF was then assayed for oxidative balance by ABTS, FRAP and TBARS assays. In order to establish the correlation between oxidative balance and embryo quality, we correlated the number of usable blastocysts (freshly transferred or frozen blastocysts) with the results from ABTS, FRAP and TBARS.

RESULTS

Follicular fluid from patients of Advanced-maternal-age (AMA group) significantly differed from the values found in the control group; the ABTS value was higher and the FRAP value was lower, in comparison to the FF from oocyte donors (control group). The lipid peroxidation was not different between those two groups. Furthermore, there was no significant correlation among the results of the assays, or when correlated with the proportion of usable blastocysts.

CONCLUSION

Ovarian oxidative balance seems to be critical for oocyte quality in advanced-maternal-age patients; however, we still need more studies on oxidative stress indicators, on a larger set of patients.

The different impact of stimulation duration on oocyte maturation and pregnancy outcome in fresh cycles with GnRH antagonist protocol in poor responders and normal responders

OBJECTIVE

To study the impact of stimulation duration on intracytoplasmic sperm injection (ICSI) - embryo transfer (ET) outcome in poor and normal responders during controlled ovarian stimulation using gonadotropin-releasing hormone (GnRH) antagonist protocol.

MATERIALS AND METHODS

This is a retrospective cohort study. There were 1481 women undergoing ICSI-ET cycles. Women with ovum pick-up number ≤3 were defined as poor responders (n = 235), and those with a number ≥4 were normal responders (n = 1246).

RESULTS

The mean stimulation duration was shorter in poor responders with pregnancy group as compared with normal responders with pregnancy group (7.8 ± 2.2 vs. 9.2 ± 1.6 days, p < 0.01). Poor responders with a shortest stimulation duration (≤6 days) appeared a higher live birth rate (≤6 days: 33.3%, 7-8 days: 20.0%, 9-10 days: 15.9%, and ≥11 days: 11.1%, p = 0.18). Normal responders with a shortest stimulation duration (≤6 days) appeared a lowest live birth rate (≤6 days: 28.6%, 7-8 days: 35.8%, 9-10 days: 33.6%, and ≥11 days: 29.3%, p = 0.61). Oocyte maturation rate was significantly lower at stimulation durations ≤6 days group (≤6 days: 67%, 7-8 days: 80%, 9-10 days: 85%, and ≥11 days: 87%, p = 0.02) in normal responders.

CONCLUSION

In ICSI-ET cycles, stimulation duration appears to have different impact on oocyte maturation, clinical pregnancy rates and live birth rates in both poor and normal responders.

Anti-oxidative function of follicular fluid HDL and outcomes of modified natural cycle-IVF

High density lipoproteins (HDL) are the main cholesterol carriers in follicular fluid (FF), the natural environment of oocyte development. Additionally, HDL have critical biological functions such as anti-oxidative capacity, which have not been studied in reproduction. Therefore, this study aimed to investigate whether the anti-oxidative function of FF-HDL is associated with fertility outcomes. From 253 women undergoing modified natural cycle (MNC)- IVF at a single academic centre FF and plasma were collected (n = 375 cycles). Anti-oxidative function of FF was mainly attributable to HDL (n = 8; 83%). FF-HDL had a higher anti-oxidative function than plasma HDL (n = 19, P < 0.001) coinciding with increased vitamin E and sphingosine 1 phosphate content (P = 0.028 each). Proteomic analysis indicated no significant differences in major anti-oxidative proteins such as paraoxonase 1, apolipoprotein (apo) A-I or apoA-IV between FF-HDL and matched plasma-HDL (n = 5), while apoC-III, apoE and apoC-II were relatively lower in FF-HDL. Finally, FF-HDL anti-oxidative function was related to a decrease in the odds of the oocyte undergoing normal fertilization, an association that persisted after adjustment for confounders (odds ratio 0.97 (0.93–1), P = 0.041). In conclusion, FF-HDL has considerable anti-oxidative properties that might be relevant for embryo quality.