Influence of Follicular Fluid and Seminal Plasma on The Expression of Endometrial Receptivity Genes in Endometrial Cells

Utilizing follicular fluid on endometrial stromal cells enhances decidualization by induced inflammation

BACKGROUND

Polycystic ovary syndrome (PCOS) is a disease associated with inflammation and the follicular fluid of this patient contains proinflammatory cytokines. Abdominal obesity (AO) is also linked to increased levels of proinflammatory cytokines. This study investigated the induction of inflammation and decidualization of in vitro cultured endometrial stromal cells (ESCs) obtained from women with a normal uterus using the follicular fluid of PCOS and non-PCOS patients with or without abdominal obesity.

METHODS AND RESULTS

Forty patients under 35 years old, referred to the Royan Institute, were divided into four groups: PCOS with AO, PCOS without AO, non-PCOS with AO, and non-PCOS without AO. Follicular fluid samples were added to the culture medium of ESCs for each group. The rate of decidualization was measured by examining decidual markers. The study also investigated morphological changes in uterine endometrial cells, cell migration rates, and gene expression across all groups. We found that the non-PCOS group without AO had the highest decidualization potential and the highest expression of decidualization markers (P ≤ 0.05). Groups with an inflammatory phenotype of PCOS or abdominal obesity showed the highest expression of decidual pathway markers. The expression levels of inflammatory and proliferative markers in the PCOS group with AO were significantly higher than in the other groups (P ≤ 0.05).

CONCLUSIONS

The inflammatory profile present in the follicular fluid may trigger the decidualization process. Consequently, in the future, follicular fluid could be utilized as a natural supplement with human cells to promote decidualization and enhance endometrial receptivity in assisted reproductive technology.

An Approach to Improve Endometrial Receptivity: Is It Beneficial to Flush The Uterine Cavity with Follicular Fluid and Granulosa Cells? A Phase III Randomised Clinical Trial

BACKGROUND

The follicular fluid (FF) of mature oocytes contains a high concentration of growth factors and cytokines that have the potential to influence implantation in either a paracrine or autocrine manner. During the physiological processes of ovulation, FF enters the fallopian tubes in conjunction with the oocyte. The purpose of this study is to evaluate implantation and clinical pregnancy rates following uterine flushing with FF and granulosa cells in infertile women with moderate male factor infertility after ovum retrieval for intracytoplasmic sperm injection (ICSI).

MATERIALS AND METHODS

This phase III randomised clinical trial enrolled 140 women with moderate male factor infertility who intended to undergo ICSI at Royan Infertility Clinic (Tehran, Iran). A computer-generated program and opaque sealed envelopes were used to randomly allocate patients to either an intervention group (n=70) or a control group (n=70). Participants in the intervention group received 2 ml of clear FF (without blood contamination) from 2 to 3 dominant follicles after oocyte retrieval. The control group only underwent uterine cavity catheterisation.

RESULTS

The intervention group had a clinical pregnancy rate of 38.5% (25/65) compared to the control group [42.9% (27/63); P=0.719] and an implantation rate of 24.1% compared to the control group (27%; P=0.408). These rates did not differ between the groups. There were no statistically significant differences between the intervention and control groups in terms of pregnancy-related complications-ectopic pregnancy, blighted ovum or anembryonic pregnancy, and abortion.

CONCLUSION

Uterine cavity flushing with FF from mature follicles following oocyte retrieval had no effect, either positively or negatively, on clinical pregnancy or implantation rates in women with moderate male factor infertility (registration number: NCT04077970).

Stress Biomarkers Transferred Into the Female Reproductive Tract by Seminal Plasma Are Associated with ICSI Outcomes

This study aimed to determine whether male stress is related to seminal stress biomarkers and pregnancy achievement in women exposed to their partner's seminal plasma (SP) in the intracytoplasmic sperm injection (ICSI) cycle. In this pilot prospective study, 20 couples undergoing ICSI, as well as 5 fertile sperm donors and 10 saliva donors, were investigated. Women were exposed to their partner's SP via unprotected sexual intercourse during the ICSI cycle and intravaginal application on the day of ovum pick-up (Day-OPU). Semen samples were collected from male partners by masturbation on the Day-OPU. Saliva and serum samples were collected prior to masturbation. Body fluids were frozen at - 80 °C until assayed. Biomarkers of activity of the sympathetic adrenomedullary axis (salivary alpha-amylase and adrenaline), sympathetic neural axis (noradrenaline and dopamine), hypothalamic-pituitary-adrenal (HPA) system (cortisol), and immune system (C-reactive protein and interleukin (IL)-18) were estimated to examine their association with SP composition and clinical pregnancy achievement. The clinical pregnancy rate was 45.0%. In the unsuccessful ICSI group, blunted levels of salivary and serum cortisol were found compared to the successful ICSI group and the fertile sperm donors. With regard to seminal markers, decreased cortisol level and elevated noradrenaline, noradrenaline/cortisol ratio, and lL-18 levels were strongly associated with ICSI failure (areas under the ROC curves were, 0.813, 0.848, 0.899, and 0.828, respectively). These findings confirm that stress response systems activity affects SP composition, which in turn is associated with ICSI outcomes in women exposed to their partner's SP during an ICSI cycle.

Differential expression of tsRNAs and miRNAs in embryo culture medium: potential impact on embryo implantation

PURPOSE

Can small RNA derived from embryos in conditioned embryo culture medium (ECM) influence embryo implantation?

METHODS

We employed small RNA sequencing to investigate the expression profiles of transfer RNA-derived small RNA (tsRNA) and microRNA (miRNA) in ECM from high-quality and low-quality embryos. Quantitative real-time PCR was employed to validate the findings of small RNA sequencing. Additionally, we conducted bioinformatics analysis to predict the potential functions of these small RNAs in embryo implantation. To establish the role of tiRNA-1:35-Leu-TAG-2 in embryonic trophoblast cell adhesion, we utilized co-culture systems involving JAR and Ishikawa cells.

RESULTS

Our analysis revealed upregulation of nine tsRNAs and four miRNAs in ECM derived from high-quality embryos, whereas 37 tsRNAs and 12 miRNAs exhibited upregulation in ECM from low-quality embryos. The bioinformatics analysis of tsRNA, miRNA, and mRNA pathways indicated that their respective target genes may play pivotal roles in both embryo development and endometrial receptivity. Utilizing tiRNA mimics, we demonstrated that the prominently expressed tiRNA-1:35-Leu-TAG-2 in the low-quality ECM group can be internalized by Ishikawa cells. Notably, transfection of tiRNA-1:35-Leu-TAG-2 into Ishikawa cells reduced the attachment rate of JAR spheroids.

CONCLUSION

Our investigation uncovers significant variation in the expression profiles of tsRNAs and miRNAs between ECM derived from high- and low-quality embryos. Intriguingly, the release of tiRNA-1:35-Leu-TAG-2 by low-quality embryos detrimentally affects embryo implantation and endometrial receptivity. These findings provide fresh insights into understanding the molecular foundations of embryo-endometrial communication.