Ethylene Glycol and Dimethyl Sulfoxide Combination Reduces Cryoinjuries and Apoptotic Gene Expression in Vitrified Laying Hen Ovary

Vitrification alters growth differentiation factor 9 and follicle-stimulating hormone receptor expression in human cumulus-mural granulosa cells

OBJECTIVE

Ovarian tissue vitrification is widely utilized for fertility preservation in prepubertal and adolescent female patients with cancer. The current literature includes reports of successful pregnancy and live birth following autografting. However, the effects of the vitrification process on cumulus-mural granulosa cells (C-mGCs)-somatic cells in ovarian tissue crucial for oocyte maturation and early embryonic development-remain unclear. This study was conducted to explore the impact of vitrification on the cellular function of C-mGCs by quantifying the expression of growth differentiation factor 9 (GDF-9), bone morphogenetic protein 15 (BMP-15), follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), connexin 37, survivin, and caspase 3.

METHODS

Mature and immature C-mGCs were obtained from 38 women with polycystic ovary syndrome who participated in an in vitro fertilization program. The C-mGCs were then divided into two groups: fresh and vitrified. The expression levels of target genes were assessed using real-time quantitative polymerase chain reaction.

RESULTS

After vitrification, GDF-9 expression was significantly decreased among both mature and immature C-mGCs, with 0.2- and 0.1-fold changes, respectively (p<0.01). Similarly, FSHR expression in the mature and immature groups was reduced by 0.1- and 0.02-fold, respectively, following vitrification (p<0.01). The expression levels of the other genes, including BMP-15, LHR, connexin 37, survivin, and caspase 3, remained similar across the examined groups (p>0.05).

CONCLUSION

Vitrification may compromise oocyte maturation through reduced GDF-9 and FSHR expression in C-mGCs after warming.

Cryopreservation Competence of Chicken Oocytes as a Model of Endangered Wild Birds: Effects of Storage Time and Temperature on the Ovarian Follicle Survival

For the conservation of endangered avian species, developing gamete preservation technologies is essential. However, studies in oocytes have not been widely conducted. In this study, assuming that the ovaries are transported to a research facility after death, we investigated the effect of ovary storage on oocytes for the purpose of cryopreserving avian female gametes by using a chicken as a model of endangered avian species. After excision, the ovaries were stored at either a low temperature (4 °C) or room temperature for 1–3 days. Ovarian follicles stored under different conditions for each period were examined by neutral red staining, histology, and gene and protein expression analysis. In addition, the pH of the storage medium after preserving the ovaries was measured. Then, ovarian tissues were vitrified to determine the cryopreservation competence. Storing the ovarian tissues at 4 °C kept the follicles viable and morphologically normal for 3 days with slow decline. In contrast, although different storage temperature did not influence follicle viability and morphology after only 1 day of storage, ovarian tissues stored at room temperature rapidly declined in structurally normal follicles, and viable follicles were rarely seen after 3 days of storage. Gene and protein expression analysis showed that apoptosis had already started on the first day, as shown by the higher expression of CASP9 under room temperature conditions. Furthermore, high expression of SOD1 and a rapid decline of pH in the storage medium under room temperature storage suggested the influence of oxidative stress associated with low pH in this condition on the follicle survivability in hen ovarian tissues. Our cryopreservation study also showed that ovarian tissues stored at 4 °C could recover after cryopreservation even after 3 days of storage. The described storage conditions and cryopreservation methods, which preserve chicken follicle survival, will lay the foundation of ovarian tissue preservation to preserve the fertility of wild female birds.

Effects of Different Vitrification Solutions and Protocol on Follicular Ultrastructure and Revascularization of Autografted Mouse Ovarian Tissue

Objective

Many attempts have been made to preserve fertility by improving the cryopreservation of the ovarian tissue. This current studyaimed to improve of direct cover vitrification (DCV) protocol on follicular preservation and angiogenesis in autografted ovarian tissue.

Materials and Methods

In this experimental study, sixty five female Balb/c mice (5-6 week-old) were anesthetized and their ovaries were dissected. The left ovaries were vitrified by DCV solution, thawed by descending concentrations of sucrose, and then autografted subcutaneously. The right ovaries were autografted with no vitrification procedure prior to transplantation. The animals were sacrificed under anesthesia on the 7thday after transplantation to obtain ovarian tissue. Follicular quality was assessed by histological and ultrastructure observations, and angiogenesis was examined by immunohistochemical staining and real-time polymerase chain reaction (PCR) analysis.

Results

The histological and ultrastructure features of the follicles preserved well after vitrification of the ovarian tissue by 10% ethylene glycol (EG) and 10% dimethyl sulfoxide (DMSO). Revascularizationwas manifested prominently in the DCV1-vitrified/grafted ovaries by von Willebrand factor (vWF) and alpha smooth muscle actin (α-SMA) immunostaining. The ovarian tissue vitrified in DCV1 protocol had higher expression levels of angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF) 7 days after autotransplantation (P<0.01).

Conclusion

These findings suggest that DCV with 10% of both EG and DMSO, is an effective cryopreservation solution for preservation of good quality follicles as well an upregulation of angiogenic factors after ovarian tissue transplantation.