Static magnetic field regulates proliferation, migration, differentiation and YAP/TAZ activation of human dental pulp stem cells

Abstract

The dental pulp stem cells (DPSCs) are a population of mesenchymal stem cells, which have multilineage potential and high proliferation. DPSCs are regarded as a promising tool for tissue regeneration of dentine, dental pulp, bone, cartilage, and muscle. Recently, magnetic materials have become commonly applied in dental clinics. Static magnetic field has been reported to regulate the proliferation, migration, or differentiation of stem cells. However, whether static magnetic fields affect DPSCs is still unknown. In our study, we investigated the effect of static magnetic field on the proliferation, migration, and differentiation of DPSCs. The results indicated that static magnetic field rearranged the cytoskeleton of DPSCs. A static magnetic field of 1 mT increased DPSC proliferation, as well as the gene expression of several growth factors such as FGF-2, TGF-β, and VEGF. Moreover, the static magnetic field promoted the migration of DPSCs by regulating MMP-1 and MMP-2 gene expression. Static magnetic field of 1 mT also induced osteo/odontogenesis and mineralization in DPSCs. Otherwise, the static magnetic field recruited YAP/TAZ to the nucleus, inhibited the phosphorylation of YAP/TAZ, and upregulated the two YAP/TAZ-regulated genes, CTGF and ANKRD1. Cytoskeleton inhibitor, cytochalasin D, obviously inhibited the nuclear localization of YAP/TAZ. When YAP/TAZ were knocked-down, the static magnetic field-induced mineralization of DPSCs was diminished. Our findings provide an insight into the effect of static magnetic field on DPSCs and provide the foundation for the future tissue regeneration.

Effects of Constant Magnetic Field to the Proliferation Rate of Human Fibroblasts Grown onto Different Substrates: Tissue Culture Polystyrene, Polyacrylamide Hydrogel and Ferrogels γ-Fe2O3 Magnetic Nanoparticles

“…For example, 4 kOe magnetic field significantly enhanced the growth of dental pulp stem cells [17]. The effect of very weak magnetic field (10 Oe) on the same stem cells was similar [18]. Human chondrocytes growth was also promoted by 6 kOe field [19].…”

Moderate SMFs attenuate bone loss in mice by promoting directional osteogenic differentiation of BMSCs

“…SMF has been commonly used in clinical practice as a tool, such as in magnetic resonance imaging (MRI). Moderate-intensity SMFs (1 mT to 1 T) were reported to enhance proliferation, migration, and dentinogenesis of dental pulp stem cells by activating the p38 mitogen-activated protein kinase pathway [35][36][37] and to induce osteo/odontogenesis and mineralization in dental pulp stem cells [37,38]. Similarly, moderate-intensity SMF also promoted neuronal differentiation in fetal rat brain neural progenitor cells [39] and induced the proliferation and osteoblastic differentiation of BMSCs [40,41].…”

Magnetic nanoparticle loaded human adipose derived mesenchymal cells spheroids in levitated culture

“…It is likely that both particle dosage, preparation, coating and surface electrostatic charge influence ADSC‐MNP osteogenesis, explaining partly this controversy. Static MF exposure was previously reported to decrease cellular cytoskeleton dynamics in MNP‐loaded stem cells 17 . Disruption of F actin polymerization with cytochalasin has been previously associated with increased adipogenic conversion and reduced osteogenesis 20 …”

“…Controversial reports about osteogenesis levels of stem cells loaded with MNP exist in the literature. Increased cellular iron content and consequent activation of Wnt/β‐catenin signaling‐mediated MMP2 expression were proposed to explain decreased osteogenic differentiation after superparamagnetic iron oxide nanoparticles loading 17 . Contrarily, other studies report increased osteogenesis in MNP loaded MSCs.…”