| Summary: | 碩士 === 國立臺灣大學 === 口腔生物科學研究所 === 97 === Post-natal human dental pulp stem cells (DPSCs) are derived from dental pulp tissue. Several reports have been demonstrated that dental pulp stem cells have high proliferation rate and multipotent differentiation capacity. By using mesenchymal stem cells surface markers – STRO-1 and CD146, DPSCs were sorted by flow cytometry and were cultured in the basal medium till cells were confluence. The medium was then changed with mineralization enhancing medium (inductional medium) for inducing DPSCs differentiation.
After cDNA microarray analysis, some genes related to cell differentiation such as ALP and BMP2 were found to be upregulated. In addition, ingenuity pathway analysis (IPA) data revealed that metallothionein mRNA expression was associated with cell mineralization, especially the expression of metallothionein 1F (MT1F) gene. Thus, we hypothesized that metallothionein 1F may play an important role in DPSCs differentiation. According to previous report, metallothionein (MT) protein is encoded from metallothionein mRNA and it can mediate a lot of intracellular regulation such as cell proliferation, differentiation and regulation of essential metals and protection of cells against oxidative injury. In this study, the effect of metallothionein on DPSCs differentiation was examined. From the results of alkaline phosphatase (ALP) staining, alizarin red S (ARS) staining and RT-PCR as well as real-time PCR analysis, it was found that cells pretreated with 50 μM-200 μM ZnCl2, were demonstrated with overexpression of endogenous metallothionein. Thus, odontoblasts related genes – DSPP and OCN genes expression were upregulated and cells were shown with better mineralization and differentiation potential than those in the control group. The results were enhanced especially in the 100 μM treated group. Our results indicated that overexpression of metallothionein 1F gene can promote DPSCs to be differentiated into odontoblasts, and shorten the time for mineralization and differentiation. In conclusion, we found metallothionein 1F is a novel factor that can enhance DPSCs differentiation.
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