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

Abstract

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 vitrifiedthawed. 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. ConclusionsThe 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.

Assessment of the optimal vitrification protocol for pre-pubertal mice testes leading to successful in vitro production of flagellated spermatozoa

“…Nevertheless, a prolonged exposure with high concentrations of low molecular weight CPAs such as DMSO during the vitrification technique causes severe toxicity (Yavin & Arav, 2007) compared with the slow freezing methodology. DMSO at high concentrations is known to potentially activate the apoptotic caspase pathway (Zhang et al, 2009). Therefore, the combination of DMSO with another CPA with rapid penetration and less toxicity such as ethylene glycol (EG) may be an alternative to vitrification medium containing only high concentrations of DMSO.…”

In vitro evaluation of the anti-apoptotic drug Z-VAD-FMK on human ovarian granulosa cell lines for further use in ovarian tissue transplantation

“…HGL5 COV434 In previous studies, it was demonstrated that the short-term culture of pancreatic islets and mice ovarian cortex cryopreserved with Z-VAD-FMK reduced post-transplantation apoptosis and subsequently improved the outcome of grafts [37,34]. Moreover, Z-VAD-FMK has been found to abolish the ischemia-mediated activation of caspases [35].…”

“…While the ability of S1P to protect follicles from chemotherapy and radiationinduced damages has been well demonstrated [25][26][27][28][29], the protective effects of S1P in cryopreserved tissue grafting studies remain controversial [30][31][32][33]. Another alternative, a permeable synthetic peptide pan-caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (Z-VAD-FMK), has only been studied once in a xenograft model of cryopreserved ovarian tissue after producing encouraging results as a therapeutic option [34]. Z-VAD-FMK has also been identified as an efficient caspase inhibitor to prevent ischemia/reperfusion injuries in the liver [35], brain [36], and pancreas [37].…”

The effect of DHEA on apoptosis and cohesin levels in oocytes in aged mice

“…The supplement DHEA increased the number of follicles in aged mice, and particularly the number of primordial and primary follicles. This effect was presumably achieved by inhibiting follicular atresia (35). Anti-γH 2 AX staining indicated that atretic follicles were rescued by suppressing DNA double-strand breaks (36).…”

“…At least 30 slides from 5 mice in each group were stained with TUNEL to obtain data on follicular atresia. Follicles were considered TUNEL-positive if either the oocyte alone, the oocyte and GCs, or oocytes were negative but > 50% of GCs were positive (35). The percentage of TUNEL-positive follicles was manually calculated by two independent blinded examiners using the Olympus Scanner.…”