Transient suppression of Wnt signaling in poor-quality buffalo oocytes improves their developmental competence

Introduction

One of the most evolutionary conserved communication systems, the Wnt signaling pathway is a major gene regulatory pathway that affects the developmental competence of oocytes and regulates most embryonic developmental processes. The present study was undertaken to modulate the canonical Wnt (Wingless/integration) signaling pathway in the poor-quality (colorless cytoplasm after Brilliant Cresyl Blue staining, BCB-) buffalo cumulus-oocyte complexes (COCs) to improve their in vitro maturation (IVM) and embryo production (IVEP) rates.

Methods

The expression of key Wnt pathway genes was initially assessed in the good (blue cytoplasm after Brilliant Cresyl Blue staining, BCB+) and poor quality (BCB-) buffalo COCs to establish a differential activity of the Wnt pathway. The BCB- COCs were supplemented with the Wnt pathway inhibitor, Dickkopf-related protein 1 (DKK1) and later subjected to IVM and IVEP along with the BCB+ and BCB- controls. The cumulus expansion index (CEI), rate of nuclear maturation (mean percentage of oocytes in the MII stage) and embryo production, and the expression of developmentally important genes were evaluated to assess the effect of Wnt pathway inhibition on the development competence of these poor-quality oocytes.

Results

The Wnt pathway genes exhibited a significantly higher expression (p < 0.05) in the poor-quality BCB- oocytes compared to the good-quality BCB+ oocytes during the early maturation stages. The supplementation of BCB- COCs with 100 ng/mL DKK1 effectively inhibited the expression of the key mediators of the Wnt pathway (β-catenin and dishevelled homolog 1, DVL1). DKK1 supplemented BCB- COCs exhibited significantly improved cytoplasmic and nuclear maturation indices, development rates and significantly elevated expression (p < 0.05) of genes implicated in germinal vesicle breakdown (GVBD) and embryonic genome activation (EGA) vis-à-vis BCB- control COCs.

Conclusion

These data indicate that inhibition of the Wnt pathway during the initial course of oocyte maturation can improve the development competence of poor-quality buffalo oocytes.

Ovarian Endometrioma Negatively Impacts Oocyte Quality and Quantity But Not Pregnancy Outcomes in Women Undergoing IVF/ICSI Treatment: A Retrospective Cohort Study

PURPOSE

To determine the impact of ovarian endometrioma per se on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes.

METHODS

This retrospective study was conducted using two groups. The endometrioma group consisted of 862 women with infertility who had ovarian endometriomas and underwent their first ovarian stimulation for IVF/ICSI treatment between January 2011 to December 2019 at a public university hospital. A non-endometrioma comparison group, comprising 862 women with other infertility factors, was matched according to maternal age, body mass index (BMI), and infertility duration. Ovarian reserve and response and IVF/ICSI and pregnancy outcomes between the two groups were analyzed. Multivariate logistic regression (MLR) analysis was conducted on the basis of clinical covariates assessed for their association with live birth.

RESULTS

The results showed that significantly lower antral follicle count (AFC), anti-Müllerian hormone (AMH), ovarian sensitivity index (OSI), oocyte maturation and fertilization rates, blastocyst rate, number of oocytes retrieved, and available embryos were found in women with endometrioma compared with the control, respectively (P < 0.05). The cumulative live birth rate per patient in women with endometrioma was lower than that of women without endometrioma (39.32% vs. 46.87%, P = 0.002). In women with endometrioma, those who underwent surgical intervention prior to IVF/ICSI treatment had higher maturation (86.03% vs. 83.42%, P = 0.003), fertilization (78.16% vs. 74.93%, P = 0.004), and top-quality embryo rates (42.94% vs. 39.93%, P = 0.097) but had fewer oocytes retrieved (8.01 ± 5.70 vs. 9.12 ± 6.69, P = 0.013) than women without surgery. However, live birth rates were comparable between women with endometrioma and women in the control group, regardless of whether they had a prior history of ovarian surgery. MLR analysis showed no correlation between endometrioma per se and live birth after being adjusted for number of top-quality embryos transferred and stage of embryo transfer.

CONCLUSIONS

The data from this study supported the conclusion that ovarian endometrioma negatively impacts oocyte quality and quantity, but not overall pregnancy outcomes, in women undergoing IVF/ICSI treatment. Endometrioma lowers the cumulative live birth rate by decreasing the number of embryos. Surgical excision of endometrioma prior to IVF/ICSI can partly improve oocyte maturation and fertilization rates but not pregnancy outcomes.