Ovarian follicle culture: advances and challenges for human and nonhuman primates

Abstract

The removal and cryo-storage of ovarian cortical biopsies is now offered as a fertility preservation option for young women. The only available option to restore fertility using this tissue is by transplantation which may not be a viable option for all patients. The full potential of this tissue to restore fertility could be achieved by the development of in vitro systems that support oocyte development from the most immature stages to maturation. The techniques of in vitro growth (IVG) combined with in vitro maturation (IVM) are being developed in human but comparing different systems has been difficult because of the scarcity of tissue and non-human primates are being used as model systems. There are many challenges to developing a complete culture system that will support human oocyte development and this review outlines the approaches being taken by several groups to support each of the stages of oocyte development using tissue from women and non-human primate models.

Is transplantation of a few leukemic cells inside an artificial ovary able to induce leukemia in an experimental model?

“…In vitro follicle growth and oocyte maturation followed by in vitro fertilization could be an option. However, despite advances in the field, viable embryos and live offspring generated by this technique have only been achieved in mice so far [32][33][34], and major challenges remain to improve culture systems in humans to obtain competent human oocytes [35]. The need to find alternative fertility-restoring solutions for these patients led us to investigate isolated follicle grafting and launch the artificial ovary concept.…”

Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

“…The majority of follicles within ovarian cortical tissue are quiescent primordial follicles, so the first consideration of an in vitro growth system should be to optimize initiation of primordial follicles growth and to support early follicle development (Telfer and Zelinski, 2013). Some paracrine or endocrine factors that might regulate these early steps of folliculogenesis have been identified (Monget et al, 2012), including the locally produced epidermal growth factor (EGF; Silva et al, 2016).…”

Pediatric and Teen Ovarian Tissue Removed for Cryopreservation Contains Follicles Irrespective of Age, Disease Diagnosis, Treatment History, and Specimen Processing Methods

“…15,16 To overcome the risk, methods are being developed to isolate immature follicles from fresh or cryopreserved ovarian tissue and grow them in vitro. 12,[17][18][19] Mature oocytes derived from this method could then be cryopreserved and used for ART to restore fertility.…”