Background: Ovarian cryopreservation by vitrification is a very effective pathway for the preservation of female fertility during radiotherapy and chemotherapy. However, damage of follicles was triggered by cryo-injure during the process of ovarian vitrification and ischemia/reperfusion during the process of ovarian transplantation. Appropriate FSH play important roles in anti-apoptosis and neoangiogenesis during ovarian follicle development.
Objective: Therefore, the purpose of this study was to investigate the effect of FSH on the revascularization and follicular survival of vitrified-warmed ovarian grafts.
Materials and tmethods: Four-week-old C57BL/6J mice with diestrus were used and the ovaries were randomized into the following three groups: fresh control group (FCG), vitrified/warmed group (VCG) and vitrified/warmed group treated with 0.3 IU/mL FSH (FSH-VG) during ovarian vitrification. After warming, the ovaries of the three groups were allotransplanted into the renal capsule of receptor mice. Assessment of follicular quantity was performed by histological analysis. The angiogenesis factors, CD31 and MMP-2, and cell survival factors, PCNA, EdU and survivin were examined by immunohistochemistry and western blot analysis. Angiogenesis was detected by vascular perfusion with the fluorescent dye 2MD-FITC-Dextran.
Results: The expression of CD31and MMP-2 were not significantly different in either VCG or FSH-VG compared with FCG, but when the ovaries were transplanted 48 hours later, the expression levels of CD31 and MMP-2 were lower for VCG than FCG (P < 0.05) and FSH-VG was not significantly different from FCG. Before transplantation, the expression levels of PCNA and survivin were lower for VCG and FSH-VG than FCG (p < 0.05), but FSH-VG was higher than VCG (p < 0.05). After 48 h of ovarian transplantation, the expression of survivin was lower for VCG than FCG (P < 0.05), but FSH-VG was not significantly different from FCG. In addition, these data were further supported by the results from detecting the 2MD-FITC-Dextran and EdU.
Conclusion: Taken together, supplementation with 0.3 IU/mL FSH during ovarian cryopreservation by vitrification increased the revascularization and follicular survival for mouse ovarian grafts through the up-regulated expression of angiogenesis and ovarian survival factors.