Cav1.2 regulated odontogenic differentiation of NG2+ pericytes during pulp injury.

Abstract

NG2+ pericytes, as the possible precursor cells of mesenchymal stem cells (MSCs), have drawn attention due to their ability to differentiate into odontoblasts. Cav1.2 is involved in the differentiation process of stem cells, but its role in the differentiation of NG2+ pericytes is not clear. The aim of the present study was to examine the role of Cav1.2 in the differentiation of NG2+ pericytes into odontoblasts. NG2+ pericytes were obtained from human dental pulp cells by magnetic-activated cell sorting. During the odontogenic differentiation of NG2+ pericytes, the effects of the Cav1.2 inhibitors, nimodipine and Cav1.2 knockdown shRNA, were analyzed by real-time polymerase chain reaction and alizarin red staining. NG2CreERT2/Rosa26-GFP lineage-tracing mice were established to further investigate the roles of NG2+ pericytes and Cav1.2 in incisor self-repair after injury in vivo. At 10min, 1day, and 3days after pulp injuries in transgenic mice, NG2-GFP+ and Cav1.2 immunofluorescence co-staining was performed on the incisors. Nimodipine treatment and Cav1.2 knockdown showed similar inhibition of calcium nodule formation and mRNA levels of osteogenic markers (DSPP, DMP1, and Runx2, p < 0.05). NG2+ pericytes migrated from their inherent perivascular location to the odontoblast layers after pulp injury. Cav1.2 showed a similar response pattern as NG2+ pericytes and gradually returned to normal levels. In addition, many co-stained areas of Cav1.2 and NG2+ pericytes, both near the perivascular and odontoblast layers, were observed. These results indicate that Cav1.2 played a vital role in the odontogenic differentiation of NG2+ pericytes, and that it might be closely linked to the NG2+ pericytes-mediated repair of dental pulp injury in vivo.