Evaluating the behavior of cultured sertoli cells in the presence and absence of spermatogonial stem cell.

Background: The complex process of spermatogenesis is regulated by various factors. Several studies have been conducted to proliferate cells involved in the spermatogenesis process, in culture by used growth factors, different hormones and feeder cells. This study was conducted to evaluate the role of Sertoli cells on gene expression of fibroblast growth factor ( FGF2 ) and glial cell derived neurotrophic factor ( GDNF ) after removal of spermatogonial stem cells (SSCs) from the culture medium.

Methods: Following isolation, bovine SSCs were co-cultured with Sertoli cells and follicular stimulating hormone (FSH) for 12 days. In the treatment group, SSCs were removed from the culture medium; in the control group no intervention was done in the culture. Colony formation of SSCs was evaluated by using an inverted microscope. Then, the expression of factors genes were assessed by quantitative RT-PCR. Data was analyzed by using paired-samples t -test.

Results: The results showed that removal of SSCs led to the increase in expression of GDNF and FGF2 . These findings suggest that loss of SSCs population or decline in its population leads to changing in behavior of somatic cells which forming niche and consequently stimulates self-renewal and inhibits differentiation of SSCs.

Conclusions: The present study showed that removal of SSCs from the culture medium could be a model for damage to SSCs; the results revealed that niche cells respond to SSCs removal by upregulation of FGF2 and GDNF to stimulate self-renewal of SSCs and abrogation of differentiation.