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.