Improvement of Expression of α6 and β1 Integrins by the Co-culture of Adult Mouse Spermatogonial Stem Cells with SIM Mouse Embryonic Fibroblast Cells (STO) and Growth Factors

Objective(s): Spermatogonial Stem Cells (SSCs) maintain spermatogenesis throughout the life of the male. Because of the small number of SSCs in adult, enriching and culturing them is a crucial step prior to differentiation or transplantation. Maintenance of SSCs and transplantation or induction of in vitro spermio-genesis may provide a therapeutic strategy to treat male infertility. This study investigated the enrichment and proliferation of SSCs co-cultured with STO cells in the presence or absence of growth factors. Materials and Methods: Spermatogonial populations were enriched from the testis of 4-6 week-old male mice by MACS according to the expression of a specific marker, Thy-1. Isolated SSCs were cultured in the presence or absence of growth factors (GDNF, GFRα1 and EGF) on STO or gelatin-coated dishes for a week. Subsequently, the authors evaluated the effects of growth factors and STO on SSCs colonization by alkaline phosphates (AP) activity and flow cytometery of α6 and β1 integrins. Results: SSCs co-cultured with STO cells and growth factors developed colonization and AP activity as well as expression of α6 and β1 integrins (P≤0/05). Conclusion: Our present SSC-STO co-culture provides conditions that may allow efficient maintenance and proliferation of SSCs for the treatment of male infertility.