Is caspase inhibition a valid therapeutic strategy in cryopreservation of ovarian tissue?

Purpose The aim of this study is to determine whether inclusion of caspase inhibitor can improve the efficacy of cryopreservation of ovarian tissue. Methods Mice were randomly assigned to the Group A (fresh control group) Group B (inclusion of caspase inhibitor) and Group C (non-inclusion of caspase inhibitor). Ovarian tissue in Group B and Group C was vitrified-thawed. TUNEL assay and Bax protein detection were measured after cryopreservation. The mice in all groups received autotransplantation. The number of days before the resumption of estrous cycles was measured daily from the 5th day after surgery, and the percentage of cells expressing PCNA in grafts was measured one month following transplantation. Results The incidence of TUNEL positive follicles in Group B was significantly higher than that in Group C. Similarly, the percentage of follicles expressing Bax protein in Group B was significantly higher than that in Group C. The number of days before the resumption of estrous cycles in Group B was significantly less than that in Group C. In addition, the percentage of follicular and stromal cells expressing PCNA of grafts in Group B was significantly higher than that in Group C. Conclusions The global caspase inhibitor Z-VAD-FMK decreases the incidence of apoptosis of ovarian tissue induced by cryopreservation, and inclusion of caspase inhibitor improves the efficacy of cryopreservation of ovarian tissue.