Inhibition of mTORC1 Signaling Pathway is a Valid Therapeutic Strategy in Transplantation of Cryopreserved Mouse Ovarian Tissue.

Background: Blockage of mTOR1 can inhibit the transformation of primordial follicles into growing follicles in the ovaries.

Objective: The aim of this study was to investigate the role of mTORC1 inhibition in the cryopreservation and transplantation of mouse ovarian tissues.

Materials And Methods: ICR (Institute of Cancer Research) mice were randomly divided into control group (autograft), cryopreservation group (cryopreservation + autograft), and mTORC1 inhibition group (cryopreservation + autograft + mTOR inhibitor). After 30 days of auto-transplantation, the follicle number of graft and kit ligand (KL) immunostaining in grafts were quantified. In addition, serum concentration of anti-Müllerian hormone (AMH) was examined by ELISA.

Results: The graft in mTORC1 inhibition group showed a significantly higher proportion of primordial follicles and a significantly lower proportion of growing follicles compared with cryopreservation group. Furthermore, a significant decrease in expression of KL (a marker gene related to follicular development) was observed in mTORC1 inhibition group in contrast to cryopreservation group. The follicle number of graft and serum AMH concentration in mTORC1 inhibition group were significantly higher than that in cryopreservation group.

Conclusion: Inhibition of mTORC1 signaling pathway is a valid therapeutic strategy in transplantation of cryopreserved mouse ovarian tissue via suppression of primordial follicle activation.