Differentiation of Human Male Germ Cells From Human Umbilical Cord-Derived Mesenchymal Stem Cells in Vitro and In Vivo.

Infertility affects 15% of couples, about 50% infertility caused by male and growing evidence suggested an increasing problems in male reproductive. Recent studies have demostrated that adult stem cells have more flexible potentials than expected, and possessed the plasticity and capacity to transdifferentiate into mutilineage cells, including germ cells. Human umbilical cord-derived mesenchymal stem cells (HUCMSCs) possess stem cell properties. In this study, we cultured HUCMSCs, and assessed the possibility of HUCMSCs differentiated into human male germ cells in vivo and in vitro, and find a new source of cells for the transplantation to the male infertility.

The ethics committee of our institution approved this study. HUCMSCs were isolated from the Wharton's jelly of the umbilical cord, clonally expanded. To investigate the capacity of differentiation in vitro, HUCMSCs were treated with human menopausal gonadotropinn (HMG) and retinoid acid (RA) in vitro. While investigate the capacity of differentiation in vivo, HUCMSCs were transplanted into the seminiferous tubules of busulfan-treated mice testes after labeled with pIRES2-EGFP or bromodeoxyuridine (BrdU). After induction in vitro, the morphologic changes of the differentiated cells were detected by phase contrast microscopy?Aelectron microscopy and transmission electron microscope?Gthe male germ cell markers were detected by immunohistochemistry, Western-blot and PT-PCR. HUCMSCs were also transplanted into the seminiferous tubules of the busulfan-treated mice by microinjection. To assess the fate of HUCMSCs in the testis, the survival?Amigration and germ cell markers of the HUCMSCs in the infertility mice testis were detected by immunohistochemistry?A immunofluorescence.

HUCMSCs can express some some molecular markers of germ cells after induction. Immunohistochemistry revealed that HUCMSCs can survive in the mice testis at least 120 days, and they can migrate from the lumens to the basement membrane then to lumens again. Immunofluorescence showed that HUCMSCs can go further differentiation in the mice favorable testicular environment, and express the germ cell markers.

These suggested that HUCMSCs may differentiate into male germ cell-like cells after induced by HMG and RA in vitro; and it could survive also in a favorable testicular environment, may differentiate into germ cell lineages. This finding may provide a new strategy for the treatment of male infertility.

No relevant conflicts of interest to declare.