Follicle activation and 'burn-out' contribute to post-transplantation follicle loss in ovarian tissue grafts: the effect of graft thickness

Abstract

This study was funded by research grants from the Israeli Science Foundation (No. 1675/10), the Israeli Jack Craps foundation and the Israel Cancer Research Fund (ICRF No. 12-3081). The authors have no competing interest to declare.

Attempts to improve human ovarian transplantation outcomes of needle-immersed vitrification and slow-freezing by host and graft treatments

“…Indeed, in three specimens, there were more follicles in the grafted thawed/warmed tissue than in the ungrafted thawed/warmed control tissue. The limited number of recovered follicles together with lack of significant differences among the groups in Ki67 staining precludes conclusions that follicular activation occurred after the short-term grafting or that there was Bburn-out^of primordial follicles, especially in the thin-sliced vitrified tissue, as described for implanted bovine tissue [14]. Alternatively, it is also possible that we did not see follicular activation and burn-out because we grafted the tissue for longer than reported in the earlier study [14].…”

“…A major obstacle in ovarian tissue transplantation is follicular loss immediately after grafting, possibly due to slow neovascularization that leads to ischemia [12,13]. Alternatively, post-transplantation follicular loss, might have been a result of primordial follicle "burn-out", as demonstrated for thinly sliced grafted bovine ovarian tissue [14], similar to that used for vitrification.…”

Follicular growth after xenotransplantation of cryopreserved/thawed human ovarian tissue in SCID mice: dynamics and molecular aspects

“…Especially molecules regulating cell growth and organ size are currently being investigated as published by Kawamura et al [14]. Furthermore, Roness et al [33] hypothesized that the increase of follicular growth might be caused by disruption of follicular growth regulation leading to “ovarian follicle burnout.” The same authors observed this phenomenon in a mouse model, after administration of the gonadotoxic agent cyclophosphamide as well as after xenotransplantation of untreated bovine ovarian tissue [34, 35]. In addition to that, Silber et al [20] observed an “over-recruitment” of resting follicles after ovarian tissue transplantation indicated by the increase of AMH to above normal levels in the recipient compared to the donor.…”

Development of caprine preantral follicles after orthotopic autotransplantation of ovarian tissue: Short communication

“…Usually, graft revascularization takes places in few days 3 and, before this, ovarian tissue will be challenged with hypoxia and consequent oxidative stress, which plays an important role in massive follicular activation and burn out of the follicular reserve. 17 An increase in progesterone plasma levels was observed from day 179 to day 195. Considering that progesterone was administered day 184 only, the initial increased levels indicate that grafts were allowing the animals to recover their reproductive/endocrine function ( Figure 2B).…”