Isolation and Identification of CXCR4-positive Cells from Human Dental Pulp Cells

Abstract Introduction In previous studies, we found expression of stromal cell–derived factor-1α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) in human dental pulp and the SDF-1α–CXCR4 axis might play a role in the recruitment of CXCR4-positive dental pulp cells (CXCR4+ DPCs) toward the damaged sites. However, the specific function of CXCR4+ DPCs in the injured dental pulp was still unknown. The purpose of this study was to isolate CXCR4+ DPCs from dental pulp cells in vitro to pave the way for further study of their characteristics. Methods CXCR4+ DPCs were isolated with magnetic-activated cell sorting (MACS). Freshly isolated CXCR4+ DPCs were identified by immunohistochemistry with light microscopy or confocal microscopy. Then the phenotypes CXCR4, stromal cell surface marker-1 (STRO-1), CD146, and CD34 in 3 groups (ie, CXCR4+ DPCs, CXCR4− DPCs, or non-sorted DPCs) were analyzed by flow cytometry after they were cultured and expanded in vitro. Results The results indicated the isolated subpopulation of DPCs was enriched with CXCR4+ DPCs, and the positive rates of STRO-1 and CD146 in CXCR4+ DPCs group were higher than CXCR4− DPCs or non-sorted DPCs groups ( P < .05). There was no expression of CD34 in each group. Conclusions We can isolate CXCR4+ DPCs from DPCs with MACS and identify them by immunohistochemistry and flow cytometry.