Sertoli Cell-Conditioned Medium Induces Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells to Male Germ-Like Cells in Busulfan-Induced Azoospermic Mouse Model

Non-obstructive azoospermia is a severe form of male infertility, with limited effective treatments. Bone marrow mesenchymal stem cells (BMSCs) can differentiate to different cell lines; therefore, transplantation of these cells is used for treatment of several diseases. Since these cells require induction factors to differentiate into germ cells, we co-transplanted bone marrow stem cells (BMSCs) with Sertoli cell-conditioned medium (SCCM) into the testis of azoospermic mice. This study was carried out in two sections, in vitro and in vivo. For in vitro study, differentiating factors (c-kit and ID4) were examined after 15 days of co-culture of bone marrow cells with Sertoli cell-conditioned medium, while for in vivo study, the azoospermia model was first created by intraperitoneal administration of a single-dose busulfan (40 mg/kg) followed by single-dose CdCl (2 mg/kg) after 4 weeks. Mice were divided into 4 groups including control (azoospermia), BMSC, SCCM, and BMSC + SCCM. Eight weeks after transplantation, samples were assessed for proliferation and differentiation via the expression level of MVH, ID4, SCP3, Tp1, Tp2, and Prm1 differentiation markers. The results showed that BMSC co-cultured with SCCM in vitro differentiated BMSC to germ-like cells. Similarly, in vivo studies revealed a higher level of BMSC differentiation into germ-like cells with significant higher expression of differentiation markers in transplanted groups compared to the control. This study confirmed the role of SCCM as an inductive factor for BMSC differentiation to germ cells both in vivo and in vitro conditions.