OBJECTIVETo explore the role of the basic fibroblast growth factor (bFGF) in the directional differentiation of bone marrow mesenchymal stem cells (BMSCs) into Leydig cells.

METHODSAfter purification and identification, we inoculated the third-generation BMSCs of SD rats onto a six-orifice board and then randomly divided them into groups A (normal saline control), B (human chorionic gonadotropin [hCG] + platelet-derived growth factor [PDGF] induction), C (hCG + PDGF + 5.0 ng/ml bFGF induction), D (hCG + PDGF + 10.0 ng/ml bFGF induction), and E (hCG + PDGF + 20.0 ng/ml bFGF induction). On the 7th, 14th and 21st day of induction, we observed the morphological changes of the cells and measured the level of testosterone (T) and expression of 3 beta hydroxy steroid dehydrogenase (3β-HSD) in the supernatant by immunofluorescence staining.

RESULTSAfter induction, the BMSCs of groups B, C, D, and E exhibited microscopic features of enlarged size, inter-connection, long-shuttle or irregular shape, adherent growth, and large round nuclei, all characteristic of Leydig cells. With the prolonging of time and enhanced concentration of bFGF, gradual increases were observed in the T level and the count of 3β-HSD-positive BMSCs in the four induction groups, with statistically significant differences between group B and groups C, D, and E (P < 0.05), as well as between group C and groups D and E (P < 0.05), but not between D and E (P > 0.05).

CONCLUSIONThe bFGF has an obvious promoting effect in the in vitro induced differentiation of rat BMSCs into Leydig cells.