Generation of male germ cells from induced pluripotent stem cells (iPS cells): an in vitro and in vivo study

Abstract

Recent studies have reported that induced pluripotent stem (iPS) cells from mice and humans can differentiate into primordial germ cells. However, whether iPS cells are capable of producing male germ cells is not known. The objective of this study was to investigate the differentiation potential of mouse iPS cells into spermatogonial stem cells and late-stage male germ cells. We used an approach that combines in vitro differentiation and in vivo transplantation. Embryoid bodies (EBs) were obtained from iPS cells using leukaemia inhibitor factor (LIF)-free medium. Quantitative PCR revealed a decrease in Oct4 expression and an increase in Stra8 and Vasa mRNA in the EBs derived from iPS cells. iPS cell-derived EBs were induced by retinoic acid to differentiate into spermatogonial stem cells (SSCs), as evidenced by their expression of VASA, as well as CDH1 and GFRα1, which are markers of SSCs. Furthermore, these germ cells derived from iPS cells were transplanted into recipient testes of mice that had been pre-treated with busulfan. Notably, iPS cell-derived SSCs were able to differentiate into male germ cells ranging from spermatogonia to round spermatids, as shown by VASA and SCP3 expression. This study demonstrates that iPS cells have the potential to differentiate into late-stage male germ cells. The derivation of male germ cells from iPS cells has potential applications in the treatment of male infertility and provides a model for uncovering the molecular mechanisms underlying male germ cell development.

Current approaches for the treatment of male infertility with stem cell therapy

“…The use of ESCs, induced pluripotent stem cells and spermatogonial stem cells as pluripotent cells and mesenchymal stem cells as multipotent cells in male infertility treatment will be described in the following sections. To generate male germ cells from pluripotent stem cells (PSC), two possible approaches are recommended: in vitro differentiation into haploid, advanced cell products (Malik & Rao, ; Xu et al, ) or in vitro differentiation and in vivo transplantation combination (Cai et al, ; Zhu et al, ). The embryoid body (EB) formation and the monolayer differentiation are two methods for in vitro producing of male germ cells from PSC (Malik & Rao, ; Yang et al, ; Zhu et al, ).…”

Stem Cells as New Agents for the Treatment of Infertility: Current and Future Perspectives and Challenges

“…Generally, there are two methods to produce male gametes from the pluripotent stem cells in vitro [20]: the monolayer differentiation and the embryoid body (EB) formation [24, 44]. Direct differentiation on monolayers of human fibroblast ensures more consistent differentiation results compared with EB formation [20].…”

“…Most often, pluripotent stem cells are induced in SSC-like stages in vitro and then transplanted into sterile mice testis [24] or ectopic, into the dorsal region of the mice, together with immature testicular cell suspension [44, 48]. It has been shown in several animal models that SSC-like cells are capable of recolonizing the testis [34, 35] and exhibit proper spermatogenesis [46].…”

Biotechnological approaches to the treatment of aspermatogenic men

“…However, in this case, the offspring production had low efficiency (7 out of 65 embryos), and the mice that were born died prematurely (five months after birth), which suggests developmental aberrations. Progress in germ cell derivation from mouse iPS cells was initially more limited because none of the groups involved could obtain offspring, although PGCs were obtained in one case (104) and gamete-like cells were also recently obtained (105). Recent advances have also been made in humans.…”