Lipid profiles of follicular fluid from cows submitted to ovarian superstimulation

Abstract

Ovarian superstimulation with exogenous gonadotropins has been extensively used to produce in vivo-derived embryos for embryo transfer in cattle. This process modifies the antral follicle microenvironment and affects oocyte and embryo quality as well the differentiation of granulosa cells. Lipids play significant roles in the cell, such as energy storage, cell structure, and fine-tuning of the physical properties and functions of biological membranes. The phospholipid (PL) contents as well as the effects of superstimulatory treatments on the PL profile of follicular fluid from cows, however, remain unknown. Therefore, to gain insight into the effects of superstimulation with follicle-stimulating hormone (FSH; P-36 protocol) or FSH combined with equine chorionic gonadotropin (eCG; P-36/eCG protocol) on the profile and abundance of PL from cows submitted or not submitted to superstimulatory protocols, were treated with these two superstimulatory protocols. As a control, non-superstimulated cows were only submitted to estrous synchronization. The follicular fluid was aspirated, the remaining cells removed and the follicular fluid stored at -80 °C until extraction. The lipid screening was performed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and this technique allowed the identification of sphingomyelins (SM) and phosphatidylcholines (PC) and phosphoethanolamines (PE). The relative abundance of the ions observed in the three experimental groups was analyzed by multivariate and univariate statistical models. The phospholipid SM (16:0) and PC (36:4) and/or PC (34:1) were less (P < 0.05) abundant in the P-36 group compared to the control or P-36/eCG groups. However, the PC (34:2) was more (P < 0.05) abundant in both group of superstimulated cows compared to the control. In summary, ovarian superstimulation seems to modulate the PL content of bovine follicular fluid with a significant increase in PC (34:2), which jointly with others PC and SM, seems to offer a suitable biomarker involved with reproductive processes successful as ovary superstimulation response and embryo development.

Equine chorionic gonadotropin drives the transcriptional profile of immature cumulus‐oocyte complexes and in vitro‐produced blastocysts of superstimulated Nelore cows

“…The animals were maintained on pasture ( Urochloa brizantha ), with ad libitum access to water and a mineral supplement. Nelore ( Bos taurus indicus ) nonlactating multiparous cows of age 5–7 years, and with body condition scores ranging from 2.0 to 3.5, were submitted to P‐36 (FSH group; n = 10) or P‐36/eCG (FSH/eCG group; n = 10) ovarian superstimulation protocols as described previously (Castilho et al, ; Fontes et al, ; Santos et al, ). Briefly, at a random stage of the estrous cycle, all animals received progesterone‐releasing vaginal inserts (1.0 g; PRIMER®, Tecnopec, São Paulo, Brazil) and estradiol benzoate (2.5 mg, i.m., Estrogin®, Farmavet, São Paulo, Brazil) on Day 0.…”

“…When FSH was combined with eCG, genes involved in oviduct contraction, and relaxation were upregulated (Fontes et al, ) along with mRNA‐encoding proteins involved in the LH receptor intracellular signaling in granulosa cells (Castilho et al, ). Furthermore, this hormonal combination was able to modify the lipid profile of follicular fluid and steroidogenic capacity, increase plasma estradiol, regulate the abundance of the VEGF system, and LHCGR mRNA, and suppress miR‐222 expression in bovine granulosa cells (Santos et al, ). However, the eCG effects on cumulus‐oocytes complexes (COCs) and embryo quality remain unknown.…”

Multiple reaction monitoring (MRM)‐profiling for biomarker discovery applied to human polycystic ovarian syndrome

“…The search for biomarkers in the FF of PCOS patients undergoing IVF is a cornerstone for understanding how this syndrome affects the ovaries and how it compromises fertility potential to the extent that these patients need ART treatments. It has been previously reported that ovarian superovulation alters the FF lipid composition in cows . In addition, although lipids have been suggested to be indicative of PCOS diagnosis, molecular diagnosis of this condition remains a challenge as it is made in the absence of specific symptoms and without validated molecular markers …”

Effect of superstimulation on the expression of microRNAs and genes involved in steroidogenesis and ovulation in Nelore cows

“…For ovarian superstimulation, as described by Santos et al [29], cows at random stages of estrous cycle received progesteronereleasing vaginal inserts (1.0 g, PRIMER ® , Tecnopec, São Paulo, SP, Brazil) and estradiol benzoate (2.5 mg, i.m., Estrogin ® , Farmavet, São Paulo, SP, Brazil) on day 0.…”

“…Therefore, the last two doses of FSH are replaced by eCG doses in the P-36/eCG protocol. Recent data in Nelore cows demonstrated the impact of superstimulatory protocols on the oviductal transcript profile [28], lipid profile of follicular fluid [29], and the expression of genes involved in LHCGR signaling in granulosa cells [30]. However, the effects of P-36 and P-36/eCG protocols on follicular development need further investigation.…”