Abstract:

Objective   To investigate the changes of GDNF expression in sertoli cells(SCs) of LPS-treated Kunming(KM) mice and its effects on spermatogonial stem cells (SSCs). Methods   SCs were isolated and purified from testes of 5～6 weeks old KM mice. The SCs were cultured and divided into four groups: the normal culture medium(group con), the medium with LPS treatment 1 day( group 1d ), treatment 2 days( group 2d) and treatment 3 days( group 3d). The medium of four groups were collected respectively as the conditioned medium. RT-PCR and Western blotting were performed to investigate the changes of GDNF expressions of four groups SCs. The SSCs from the testes of 5～7days KM mice were isolated and cultured, and divided into four groups: con, groupⅠ, group Ⅱ and group Ⅲ. The SSCs were cultured for 96 hours in the conditioned medium respectively. Immunofluorescent staining was performed on SSCs to investigate the expressions of PLZF, oct4, PCNA, c-kit and sohlh2. RT-PCR was performed to investigate the expressions of Gfrα1, c-ret, Bcl6b and Etv5. Results   RT-PCR and Western blotting results revealed that the expression of GDNF in SCs was decreased in the order of group con, group 1d, group 2d and group 3d. Immunofluorescence and RT-PCR results revealed that the expressions of PLZF, oct4 and PCNA in SSCs were decreased in the order of group con, group 1d, group 2d and group 3d, and the expressions of c-kit and sohlh2 were increased in the order of group con, group 1d, group 2d and group 3d. RT-PCR results revealed that the expressions of Gfrα1, c-ret, Bcl6b and Etv5 in group 1d, group 2d and group 3d were decreased compared with group con. Conclusion     The expression of GDNF in LPS-treated mouse SCs is decreased. The differentiation and self-renewal of SSCs can be stimulated and inhibited respectively by the reduction of GDNF expression in SCs via down-regulation of Bcl6b and Etv5 expression.

Key words: Lipopolysaccharide； Sertoli cells； Glial cell-line derived neurotrophic factor； Spermatogonial stem cells； Differentiation；   Self-renewal