[Differentiation of human bone marrow mesenchymal stem cells into Leydig or steroidogenic cells in vitro]

To investigate the possibility of differentiating mesenchymal stem cells (MSCs) into steroidogenic or testicular Leydig cells in vitro.

The 3rd-passage cells of MSCs were divided into 4 groups to be induced and cultured. The experimental groups were cultured with conditional medium which consisted of luteinizing hormone (LH), human chorionic gonadotrophin (hCG), platelet-derived growth factor (PDGF) and interlukin-1alpha (IL-1alpha) as follows. Group A: LH 0.75 U/mL, hCG 40 U/mL,PDGF 10 ng/mL, IL-1alpha 0.0005 ng/ mL; Group B: LH 0.375 U/mL, hCG 20 U/mL, PDGF 10 ng/mL, IL-1alpha 0.0005 ng/mL; Group C: LH 0.1875 U/ mL,hCG 10 U/mL, PDGF 10 ng/mL, IL-1alpha 0.0005 ng/mL. Meanwhile, the control group was cultured in basal medium with normal sodium. The results were analysed by microscopic observations, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) immunocytochemistry and immunofluorescence on the 7th, 14th and 21st day of induction respectively. The function of the induced cells was characterized by testosterone ELISA.

10-14 days after induction, the induced cells with a typical reticular intercellular connection possessed the morphologic characteristic of Leydig cells. 3beta-HSD immunocytochemistry and immunofluorescence showed that Group A at 21th day had the most positive cells (P < 0.05). 21 days of induction revealed a higher testosterone production than others (P < 0.05).

MSCs from human bone marrow are able to differentiate into steroidogenic or testicular Leydig cells in vitro. Human bone marrow-derived MSC may become important cells for studies of steroidogenic differentiation and offer a potential clinical stem cell source for diseases of steroidogenic organs.