engleski

Osteogenic potential and stemness of mesenchymal stem cells after dexamethasone treatment

The purpose of the research was to improve osteogenic differentiation of human bone marrow derived-mesenchymal stem cells (hMSCs) and to evaluate the level of remaining undifferentiated stem cells in culture. Standard cell culture protocol includes continuous exposure to the dexamethasone which is not easy to reproduce in human body. Therefore, our experiment was designed to investigate the possibility of using short-term dexamethasone exposure in order to induce osteogenic differentiation. Human bone marrow-derived MSCs were expanded with FGF-2 supplemented media. Afterwards cells were cultured in osteogenic media (DMEM low glucose, 10% FBS, 10mM β-glycerophosphate, 5μg/ml ascorbic acid, 1mM piruvat) and treated with different concentrations of dexamethasone, both short-term and continuous. The differentiation status of the cells was estimated using several osteogenic markers - alkaline phosphatase (AP) activity, the bone sialoprotein (BSP) and dentin matrix protein 1 (DMP-1) mRNAs. The stemness of the cells was estimated by the presence of pluripotency markers - SRY (sex determining region Y)-box 2 (SOX2) and octamer-binding transcription factor 4 (OCT4). The measurements were conducted on the days 7 and 14 after osteogenic conditions had been introduced. Our results show that continuous treatment induces the highest level of osteogenesis, but 2 hour exposure also induced differentiation in comparison with control. Overall, 10-5 M concentration of dexamethasone was the most powerful in the short-term induction of osteogenesis. SOX2 has not been detected in hMSCs. OCT4 was expressed in undifferentiated pluripotent hMSCs and its expression subsequently went down, indicating that the differentiation process is proceeding

MSC; stemness; dexamethasone

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