Transplantation of Spermatogonial Stem Cells Suspension into Rete Testis of Azoospermia Mouse Model

The loss of spermatogonia following chemo-or radiotherapy leading to temporary or permanent infertility of the patient is a well known and unwanted side effect of many oncological therapies.
In this study, germ cells were isolated from 4 days old mouse testis cells. Busulfan treatment was used to the eliminate proliferating cells in the testis of recipient mice. The donor cells suspended in DMEM, were introduced into the rete testis of recipient mice via microinjection method. To distinguish the progeny of the transplanted donor stem cells from endogenous germ cells, BrdU-labeled cells were used. In addition, real time PCR was performed to determine expression levels of ngn3 and LIN28 (spermatogonia stem cells markers) before and after transplantation. Western blot analysis was further performed to detect an increase in - ngn3 expression after transplantation.
Transplantations of stem cells into rete testis of the recipients was done. Our results clearly showed a significant increase in spermatozoa number in epididymal luman Spermatogonial stem cells (SSCs) did not show alkaline phosphatase activities while ngn3 and LIN28 were clearly expressed. Ngn3 and LIN28 expression were reduced after busulfan treatment compared to untreatmented mice. However, the expression of ngn3 and LIN28 increased after transplantation . BrdU-labeled testis cells were successfully transplanted into rete testis of recipient mice. These cells remained in rete testis of all recipient mice up to two months after transplantation.
The present study clearly confirme that a regeneration after cytotoxic treatment was based on morphological criteria. We demonstrated the increase in stem cell numbers during regeneration and after transplantation. Transplantation of spermatogonial stem cells suspension by the injection of cells via the rete testis of recipient azoospermia model considerably enhances the efficiency of this procedure.