Controlled ovarian hyperstimulation cycle: alterations in redox status of the follicular fluid.

149 p.Los ciclos de hiperstimulación ovárica controlada son ampliamente utilizados en las técnicas de reproducción asistida debido al mayor número de óvulos que se obtienen por ciclo y al consecuente aumento de las probabilidades de éxito de los tratamientos. Sin embargo, la manipulación hormonal que conllevan estos ciclos puede producir efectos adversos tanto a nivel ovárico como gestacional, entre ellos alteraciones redox. En esta tesis doctoral se ha estudiado el sistema antioxidante del líquido folicular (microambiente del ovocito) de una misma mujer después de un ciclo de ovulación natural y después de un ciclo de hiperestimulación ovárica controlada. Para ello se han utilizado técnicas espectrofotométricas, espectrometría de masas, inmunotransferencia western, técnicas de cultivos celulares y microscopia confocal. Los resultados mostraron que los ciclos de hiperestimulación ovárica provocan una disminución de la protección antioxidante del líquido folicular y por tanto del ovocito, frente a los ciclos naturales en los que el ovocito se encuentra más protegido. Esto se vio reflejado, entre otras cosas, en una disminución de la actividad de los enzimas PON, los cuales hemos caracterizado por primera en las células de la granulosa humanas, lo que nos lleva a sugerir un posible papel en los procesos reproductivos

Evidence of Paraoxonases 1, 2, and 3 Expression in Human Ovarian Granulosa Cells

Increasing evidence suggests that the antioxidant paraoxonase proteins, PON1, PON2, and PON3, have a role in reproduction and may be synthesized by ovarian cells. The aim of this work was to investigate whether human ovarian granulosa cells (GC) express paraoxonases 1, 2, and 3 (PON1, PON2, and PON3) at both the transcriptional and protein levels. Cells were purified from follicle samples of women undergoing ovarian stimulation at oocyte retrieval. We analyzed mRNA by polymerase chain reaction using specific primers for the different variants and quantified the proteins by Western blot using commercially available human recombinant PON proteins as standards. The protein subcellular distribution was determined by immunofluorescence and confocal microscopy and the cell cycles by flow cytometry. Thymidine was used for cellular synchronization at G1/S. Human hepatoma HepG2 and immortalized granulosa COV434 cell lines were used to optimize methodologies. mRNAs from PON1, the two variants of PON2, and PON3 were detected in GC. The cells actively secreted PON1 and PON3, as evidenced by the protein detection in the incubation medium. PON1 and PON3 were mainly distributed in the cytoplasm and notably in the nucleus, while PON2 colocalized with mitochondria. Subcellular nucleo-cytoplasmic distribution of PON1 was associated with the cell cycle. This is the first evidence describing the presence of mRNAs and proteins of the three members of the PON family in human ovarian GC. This study provides the basis of further research to understand the role of these proteins in GC, which will contribute to a better understanding of the reproduction process.This work was supported by research grants from the University of the Basque Country UPV/EHU (General Support to Research Groups, refs. GIU16/62 and GIU20/021), and Basque Government (pre-doctoral grant to I.P.-R.)

Analysis of Protein Oxidative Modifications in Follicular Fluid from Fertile Women: Natural Versus Stimulated Cycles

Oxidative stress is associated with obstetric complications during ovarian hyperstimulation in women undergoing in vitro fertilization. The follicular fluid contains high levels of proteins, which are the main targets of free radicals. The aim of this work was to determine specific biomarkers of non-enzymatic oxidative modifications of proteins from follicular fluid in vivo, and the effect of ovarian stimulation with gonadotropins on these biomarkers. For this purpose, 27 fertile women underwent both a natural and a stimulated cycle. The biomarkers, glutamic semialdehyde (GSA), aminoadipic semialdehyde (AASA), N-epsilon-(carboxymethyl)lysine (CML), and N-epsilon-(carboxyethyl)lysine (CEL), were measured by gas-liquid chromatography coupled to mass spectrometry. Results showed that follicular fluid contained products of protein modifications by direct metal-catalyzed oxidation (GSA and AASA), glycoxidation (CML and CEL), and lipoxidation (CML). GSA was the most abundant biomarker (91.5%). The levels of CML amounted to 6% of the total lesions and were higher than AASA (1.3%) and CEL (1.2%). In the natural cycle, CEL was significantly lower (p < 0.05) than in the stimulated cycle, suggesting that natural cycles are more protected against protein glycoxidation. These findings are the basis for further research to elucidate the possible relevance of this follicular biomarker of advanced glycation end product in fertility programs.This research was funded by the Basque Government, Department of Education, Universities and Research (project ref. IT687-13 and predoctoral grant to I.P.) and Department of Economic Development and Competitiveness, SPRI (refs. IG-20130001214 and IG-2014 0000837), University of the Basque Country UPV/EHU (ref. GIU16/62), and Fundacion Jesus Gangoiti (grant to S.M.)

Meta-Analysis of the Embryo Freezing Transfer Interval

Background The decision of whether frozen embryo transfer (FET) should be performed in the cycle immediately after OPU or at least one cycle later is controversial. FET could improve pregnancy rates in IVF; however, how much time is needed for the endometrium to return to optimal receptivity after ovarian stimulation is not known. Methods Electronic search in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials to identify studies providing data on the influence of the interval between embryo freezing (or OPU) and FET in FET cycles published between January 1, 2007, and February 1, 2020. Main findings Data analyzed indicated that in the immediate FET cycles, there was a trend to an increased biochemical pregnancy rate (RR = 1.08; CI = 1.00-1.18), whereas the clinical pregnancy rate was somewhat higher, but without reaching statistical significance (RR = 1.07; CI = 0.99-1.15). The live birth rate was similar in the two groups (RR = 1.05; CI = 0.95-1.15), as was the implantation rate (RR = 0.98; CI = 0.83-1.16). Stratifying by embryo stage or FET type (freeze-all or FET after failed fresh transfer) showed no differences. Conclusion Systematically delaying FET does not offer benefits to IVF outcomes. In addition, immediate transfer is associated with a nonsignificant trend to better clinical pregnancy rate and it also avoids the psychological effects of prolonging the stress on prospective parents

Effect of vitamin E administered to men in infertile couples on sperm and assisted reproduction outcomes: a double-blind randomized study

Objective: To evaluate the influence on sperm parameters and invitro fertilization (IVF) outcomes of the administration of 400 mg/day of vitamin E for 3 months to men from infertile couples who are undergoing IVF. Design: Double-blind, placebo-controlled, randomized study. Setting: Human reproduction unit of a university hospital. Patients: A total of 101 couples, 50 in the vitamin E group and 51 in the placebo group, undergoing IVF, among whom 64.4% of cases had an abnormal spermiogram according to World Health Organization (WHO) criteria. Interventions: Vitamin E (alpha-tocopherol), 400 mg daily by mouth for 3 months, with sperm analysis performed immediately before starting the treatment and 3 months later on the day of IVF. Main Outcome Measures: WHO sperm parameters and IVF outcomes. Results: Although there was a statistically significant increase in progressive motility in the vitamin E group compared with before-treatment values, a similar increase occurred in the placebo group. Normal morphology was even better in the placebo group. Regarding IVF outcomes, better fertilization rates were observed in the placebo group, but the live-birth rate per transfer was statistically significantly higher in the vitamin E group: 17 (41.46%) of 41 versus 9 (20.46%) of 44 in the placebo group. Although the clinical pregnancy rates (both per transfer and per cycle started) and the implantation rate were somewhat higher in the vitamin E group (43.9% and 25%; 36.0% and 22.0%; and 24.7% and 14.1%, respectively), the increase was not statistically significant. Conclusions: The effect of vitamin E on classic sperm parameters was not an improvement over placebo. Nonetheless, vitamin E administration was associated with a statistically significantly higher live-birth rate, and there was a trend toward better results in other IVF parameters

Classification of Common Food Lipid Sources Regarding Healthiness Using Advanced Lipidomics: A Four-Arm Crossover Study

publishedVersio