Role of Sex Hormone Receptors in Ovulation

Forecasting early onset diminished ovarian reserve for young reproductive age women

PURPOSE

To investigate the biological networks associated with DOR in young women and the subsequent molecular impact on preimplantation embryos.

METHODS

Whole peripheral blood was collected from patients: young women presenting with diminished ovarian reserve (DOR) and age-matched young women with normal ovarian reserve. Maternal exome sequencing was performed on the NovaSEQ 6000 and sequencing validation was completed using Taqman® SNP Genotyping Assays. Blastocyst global methylome and transcriptome sequencing were also analyzed.

RESULTS

Exome sequencing revealed 730 significant DNA variants observed exclusively in the young DOR patients. Bioinformatic analysis revealed a significant impact to the Glucocorticoid receptor (GR) signaling pathway and each young DOR female had an average of 6.2 deleterious DNA variants within this pathway. Additional stratification based on patient age resulted in a cut-off at 31 years for young DOR discrimination. Embryonic global methylome sequencing resulted in only a very small number of total CpG sites with methylation alterations (1,775; 0.015% of total) in the DOR group. Additionally, there was no co-localization between these limited number of altered CpG sites and significant variants, genes, or pathways. RNA sequencing also resulted in no biologically significant transcription changes between DOR blastocysts and controls.

CONCLUSION

GR signaling DNA variants were observed in women with early-onset DOR potentially compromising oocyte production and quality. However, no significant downstream effects on biological processes appear to impact the resulting blastocyst. The ability to forecast premature DOR for young women may allow for earlier identification and clinical intervention for this patient population.

Effects of dehydroepiandrosterone supplementation on women with poor ovarian response: A preliminary report and review

OBJECTIVE

To investigate the effect of dehydroepiandrosterone (DHEA) supplementation on women with poor ovarian response (POR).

MATERIALS AND METHODS

Women with POR treated with flexible daily gonadotropin-releasing hormone antagonist in vitro fertilization (IVF) cycles at The Reproductive Center in Kaohsiung Veterans General Hospital between January 2013 and October 2013, were enrolled for this prospective study. When patients failed to become pregnant during the first IVF cycle, they were treated with DHEA supplementation (30 mg, 3 times a day, orally) for 3 months (mean 12.2 weeks) before the next IVF cycle. Parameters of biochemical, ultrasound and treatment outcomes were compared before and after DHEA supplementation.

RESULTS

Ten patients with a mean age of 36.6 ± 4.2 years were identified. After DHEA treatment, there was a significant increase in antral follicle count, from 2.8 ± 1.0 to 4.1 ± 1.2 (p < 0.05), and anti-Müllerian hormone, from 0.4 ± 0.2 ng/mL to 0.84 ± 0.2 ng/mL (p < 0.001). A significant decrease of Day 3 follicle-stimulating hormone and estradiol, from 14.4 ± 1.7 mIU/mL to 10.1 ± 0.7 mIU/mL and from 51.2 ± 6.3 pg/mL to 35.2 ± 4.2 pg/mL, respectively (both p < 0.001), was noted. Increased numbers of retrieved oocytes (from 2.4 ± 1.1 to 4.2 ± 1.2; p < 0.01), fertilized oocytes (from 1.7 ± 0.5 to 3.8 ± 1.1; p < 0.001), Day 3 embryos (from 1.7 ± 0.5 to 3.7 ± 1.1; p < 0.001) and transferred embryos (from 1.7 ± 0.8 to 2.8 ± 0.8; p < 0.01) were also seen in these women with POR after DHEA treatment. Three women became pregnant after DHEA treatment.

CONCLUSION

The potential benefits of DHEA supplementation in women with POR were suggested by the biochemical parameters and IVF outcomes.

Gene expression of cumulus cells in women with poor ovarian response after dehydroepiandrosterone supplementation

OBJECTIVE

Our previous study showed the potential benefits of dehydroepiandrosterone (DHEA) supplementation in women with a poor ovarian response (POR). Because the connection between cumulus cells (CCs) and oocytes is a key step for oocyte maturation, we supposed that altered gene expression of CCs in women with POR after DHEA supplementation might favor oocyte maturation.

MATERIALS AND METHODS

Women with POR treated with flexible daily gonadotropin-releasing hormone antagonist in vitro fertilization (IVF) cycles at The Reproductive Center in Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan between January 2013 and October 2013 were enrolled for this prospective study. CCs were isolated during IVF before and after DHEA (CPH-Formulation, Oakdale, CA, USA) supplementation. Nine genes of isolated CCs, including hyaluronan synthase (HAS2), versican (VCAN), thrombospondin 1 (THBS1), runt-related transcription factor 2 (RUNX2), chromobox homolog 3 (CBX3), tripartite motif-containing 28 (TRIM28), B-cell lymphoma 2 (BCL2), BCL2-associated X protein (BAX), and ankyrin repeat domain 57 (ANKRD57), were compared.

RESULTS

There was a significant difference in the expression of genes in women with POR before and after DHEA supplementation (all p < 0.05). All genes related to extracellular matrix (ECM) formation, including HAS2, VCAN, and THBS1, were upregulated. By contrast, all genes involving cell development, differentiation, and apoptosis regulation were downregulated. Unknown function gene ANKRD57 was also downregulated after DHEA supplementation. Although expressions of both BCL2 and BAX were decreased in women with POR after DHEA supplementation compared to those before treatment, the ratio of BCL2 and BAX was significantly increased in women with POR after DHEA supplementation, suggesting that DHEA supplementation might activate the antiapoptosis process of CCs, which might be beneficial to the improvement of ovarian function in women with POR.

CONCLUSION

The study showed that DHEA therapy positively affected the gene expression of CCs in women with POR, and provided evidence to support the positive effect of DHEA supplementation on women with POR.

Molecular characterization and tissue distribution of estrogen receptor genes in domestic yak

Estrogen and its receptors are essential hormones for normal reproductive function in males and females during developmental stage. To better understand the effect of estrogen receptor (ER) gene in yak (Bos grunniens), reverse transcription-polymerase chain reaction (PCR) was carried out to clone ERα and ERβ genes. Bioinformatics methods were used to analyze the evolutionary relationship between yaks and other species, and real-time PCR was performed to identify the mRNA expression of ERα and ERβ. Sequence analysis showed that the ER open reading frames (ORFs) encoded 596 and 527 amino acid proteins. The yak ERα and ERβ shared 45.3% to 99.5% and 53.9% to 99.1% protein sequence identities with other species homologs, respectively. Real-time PCR analysis revealed that ERα and ERβ were expressed in a variety of tissues, but the expression level of ERα was higher than that of ERβ in all tissues, except testis. The mRNA expression of ERα was highest in the mammary gland, followed by uterus, oviduct, and ovary, and lowest in the liver, kidney, lung, testis, spleen, and heart. The ERβ mRNA level was highest in the ovary; intermediary in the uterus and oviduct; and lowest in the heart, liver, spleen, lung, kidney, mammary gland, and testis. The identification and tissue distribution of ER genes in yaks provides a foundation for the further study on their biological functions.

Effect of gonadotropin-releasing hormone agonist on ES-2 ovarian cancer cells

OBJECTIVE

Gonadotropin-releasing hormone (GnRH) receptor is found in the ovarian tissue, including epithelial ovarian cancer (EOC), suggesting that GnRH agonists may have direct action on EOC.

MATERIALS AND METHODS

Ovarian clear cell cancer (ES-2) cells were treated with low-dose GnRH agonist with/without low-dose paclitaxel (1 μM D-Lys(6) with/without 0.5 μM or 1.0 μM paclitaxel). Growth and behavior of ES-2 cells were evaluated.

RESULTS

Use of either D-Lys(6) or paclitaxel or a combination of the two did not affect the morphology and growth pattern of ES-2 cells. However, ability of migration and invasion of ES-2 cells was significantly decreased in either use of D-Lys(6) or paclitaxel and more apparent with the combination. Type I GnRH receptor expression of ES-2 was not altered significantly by the combination.

CONCLUSION

GnRH agonist might modify the ES-2 ovarian cancer cells, and its role might be independent, additional or synergistic, suggesting the potential role of the use of GnRH agonist in the management of clear cell type of the ovarian cancer. However, the results of this study were derived using ES-2 ovarian cancer cells, and might not be valid in other cell types of ovarian cancers.