ABSTRACT
OBJECTIVE: Runt-related transcription factor 2 (RUNX2) and osterix (OSX) as two specific osteoblast transcription factors and distal-less homeobox 5 (DLX5) as a non-specific one are of paramount importance in regulating osteoblast related genes including osteocalcin, bone sialoprotein (BSP), osteopontin and collagen type Iα1. The present study sets out to investigate whether epigenetic regulation of these genes is important in osteoblastic differentiation of mesenchymal stem cells (MSCs). MATERIALS AND METHODS: In this experimental study, MSCs were differentiated to osteoblasts under the influence of the osteogenic differentiation medium. DNA and RNA were extracted at days 0, 7, 14 and 21 from MSCs differentiating to osteoblasts. Promoter regions of RUNX2, OSX, DLX5 and BSP were analyzed by methylation-specific PCR (MSP). Gene expression was analyzed during osteoblastic differentiation by quantitative real-time polymerase chain reaction (PCR). RESULTS: MSP analysis revealed that promoter methylation status did not change in RUNX2, DLX5 and BSP during MSC osteoblastic differentiation. In contrast, OSX promoter showed a dynamic change in methylation pattern. Moreover, RUNX2, OSX, DLX5 and BSP promoter regions showed three different methylation patterns during MSC differentiation. Gene expression analyses confirmed these results. CONCLUSION: The results show that in differentiation of MSCs to osteoblasts, epigenetic regulation of OSX may play a leading role.
ABSTRACT
Oligodendrocytes are myelinating cells in the central nervous system that form the myelin sheath of axons to support rapid nerve conduction. MicroRNAs have critical roles in oligodendrocyte development. Several studies have shown that miR-219 is necessary to promote oligodendrocyte differentiation through repressing negative regulators of oligodendrocyte development. Human endometrial-derived stromal cells (EnSCs) are abundant and available adult stem cells with low immunological incompatibility, which could be considered for cell replacement therapy in future. After induction of EnSCs by FGF2, EGF and PDGF-AA, they were infected by miR-219-GFP-expressing lentiviruses. The cells were analyzed for expression of stage-specific oligodendrocyte cells markers. Quantitative RT-PCR and immunocytochemistry analyses showed that stage-specific markers Nestin, Olig2, Sox10, PDGFRa, CNP, A2B5, O4, and MBP are expressed in their specific stages through differentiation protocol. Results showed that expression of pre-oligodendrocyte markers in miR-219-GFP-expressing cells were higher than triiodothyronine (T3) treated cells. In conclusion, the EnSCs could be programmed into pre-oligodendrocyte cells by overexpression of miR-219, and may convince to consider these cells as safe source for cell replacement therapy of neurodegenerative diseases.
