Investigation on the Effect and Mechanism of Static Magnetic Field Coupled with Magnesium Ion for Promoting Odontogensis and Migration of Wharton'S Jelly Mesenchymal Stem Cells

Direct pulp capping or partial pulpotomy is a treatment to preserve the vitality of exposure pulp tissue. Within the treatments, to generate the odontoblast-like cells, the quiescent dental pulp stem cells (DPSCs) were activated and proliferation. Later, the DPSCs will migrate to the traumatic site and differentiate into odontoblast-like cells to replace necrotic odontoblasts. Then a layer of reparative dentin formation was expected. However, for an aging patient, the vitality and activity of DPSCs are reduced. Then stem cells from other resources are needed to complete this healing process. It was reported that human Wharton's jelly mesenchymal stem cells (hWJMSCs) exhibits potential to differentiate to odontoblast-like cells. In addition, previous reports showed that static magnetic fields (SMFs) and magnesium ion (Mg2+) has positive effect on the cell proliferation, migration and differentiation. Thus in this study proposal, a series of experiment was designed to test whether SMF coupled with Mg2+ provide additional effects on the stem cell migration and odontogenesis. For methodology, the hWJMSCs will be cultured in medium containing various concentrations of Mg2+. The co-effect of Mg2+ coupled with SMF will be evaluated by culturing the WJMSCs in medium containing Mg2+ and exposed to 0.4T SMF. To evaluate the effect of 0.4-T SMF and magnesium ion on WJMSC migration, in vitro scratch assay will be performed. Cytoskeleton will be identified by fluorescence immunostaining. DMP-1 and DSPP genes will be analyzed with quantitative real time-polymerase chain reaction (qRT-PCR). Finally, the odontogenic WJMSCs will be stained with Alizarin Red S for calcified depositions evaluation. In addition, Real-time PCR was used to check the characteristic proteins, including OCN, BMPs, ALP and RUNX2 of the physical and chemical stimulated WJMSCs. To analyze the role of p38 MAPK in the effects of migration or odontogenesis by SMF/Mg2+, p38 inhibitor (SB203580) was incorporated into the in above experiments. In addition, p38 related makers, MAPK 11 and MAPK 14 will be detected. After finish all the experiments, we will provide a new method for promoting stem cells differentiation and a new vision for the treatment of pulp disease. The results of this study will be a useful guide and reference for future advanced investigations and applications of regenerative medicine and oral medicine.