Generation of human oogonia from induced pluripotent stem cells in vitro

Abstract

Human in vitro gametogenesis may transform reproductive medicine. Human pluripotent stem cells (hPSCs) have been induced into primordial germ cell–like cells (hPGCLCs); however, further differentiation to a mature germ cell has not been achieved. Here, we show that hPGCLCs differentiate progressively into oogonia-like cells during a long-term in vitro culture (approximately 4 months) in xenogeneic reconstituted ovaries with mouse embryonic ovarian somatic cells. The hPGCLC-derived oogonia display hallmarks of epigenetic reprogramming—genome-wide DNA demethylation, imprint erasure, and extinguishment of aberrant DNA methylation in hPSCs—and acquire an immediate precursory state for meiotic recombination. Furthermore, the inactive X chromosome shows a progressive demethylation and reactivation, albeit partially. These findings establish the germline competence of hPSCs and provide a critical step toward human in vitro gametogenesis.

Functional Oocytes Derived from Granulosa Cells

“…Moreover, the derived gPSCs show high germline competence and genome integrity and thus are ideal for rejuvenation of functional oocytes for preserving or restoring fertility, as well as for regenerative medicine. Recently, PGCLCs have been successfully induced from human ESCs (hESCs) or human iPSCs (hiPSCs) (Irie and Surani, 2017;Irie et al, 2015;Sasaki et al, 2015), and encouragingly, these hESC-or hiPSC-derived PGCLCs can differentiate into oogonia (Yamashiro et al, 2018). In human fertility clinics, retrieved oocytes are used for IVF, but the GCs accompanied by oocytes are often discarded as by-products.…”

iPSC-Derived Ovarian Tissue Restores Ovarian Function in Subfertile Mice and After Gonadotoxic Chemotherapy

“…In the current work, we show that this stem cell-derived ovarian cortex also supports increased generation of differentiating stem cells that express oocyte markers, presumably a larger cohort of primitive oogonia. While the feasibility of generating stem cell derived oocytes using reconstituted ovarian tissue has been described 18 , our work for the first time shows that oocyte development and the supporting ovarian cortical matrix can both be promoted directly from induced pluripotent stem cells 31,32 . A key observation in these studies is the capacity for differentiated, sorted mGriPSCs to contribute to the de novo generation of oocytes, as well as form ovarian follicles as evidenced by the GFP labelled follicular granulosa cells.…”

Gametes from stem cells: Status and applications in animal reproduction

“…Lastly, new ESC lines were derived from blastocysts generated using these oocytes. In humans, culture of in vitro‐derived PGCLCs in xenogeneic reconstituted ovaries using foetal somatic mouse cells led to the generation of human oogonia‐like cells (Yamashiro et al, ), representing a critical step towards in vitro gametogenesis in humans. The degree of success achieved in the different animal species up to date is summarized in Figure .…”