Abstract: Objective To find out whether there is any alteration of KLF2 and KLF15 gene expression during the process of induced adipogenic, osteogenic, and myogenic differentiation from human bone marrow mesenchymal stem cells (hBMSCs) in vitro, and to discuss the possible roles of KLF2 and KLF15 in these processes. Methods Cells were isolated by density gradient centrifugation from human bone marrow. Surface markers were analyzed by flow cytometry. Cultures in the 4th passage were treated with established lineage-specific agents in vitro and confirmed by Oil red O, Alizarin red S, myosin immunofluorescent staining, and several differentiation marker genes expression. Meanwhile, the expression of KLF2, KLF15 and GLUT4 were detected by quantitative RT-PCR and immunofluorescent staining. Results The hBMSCs expressed markers of mesenchymal stem cells, CD29 and CD90. Cultures in the 4th passage gained the ability to undergo lineage commitment after exposure to adipogenic,osteogenic, and myogenic stimuli, and expressed specific markers. Both KLF2 and KLF15 showed characteristic time-course expression during adipogenesis, osteogenesis, and myogenesis. Conclusion KLF2 and KLF15 are possibly related to the initiation and maintenance of hBMSCs adipogenesis, osteogenesis, and myogenesis; KLF2 and KLF15 may affect hBMSCs differentiation through GLUT4 mediated energy metabolism.

Key words: bone marrow mesenchymal stem cell, commitment differentiation, KLF2, KLF15