Required Time for Migration of Bone Marrow–derived Cells to Dental Pulp after Bone Marrow Transplantation

Abstract Introduction This study aimed to evaluate the time required for bone marrow–derived cells (BMDCs) from transgenic green fluorescent protein (GFP)+ donor mice (GFP+ mice) to migrate into the dental pulp of wild-type GFP– recipient mice (GFP– mice) by using bone marrow transplantation (BMT) as an in vivo model for tracking BMDCs from GFP+ mice (GFP+ BMDCs). Methods GFP+ BMDCs were injected into irradiated GFP– mice. Maxillary arches, tibiae, and femora from GFP– mice were isolated and processed at 24 hours, 48 hours, 4, 7, and 14 days, and 7 weeks after BMT. Confocal laser microscopy analyses were performed to assess the presence of GFP+ BMDCs in the dental pulp, and flow cytometry of BM was performed to confirm the efficiency of engraftment of GFP+ BMDCs. Results Confocal laser microscopy analyses evidenced the presence of GFP+ BMDCs in the dental pulp of GFP– mice from 14 days to 7 weeks after BMT. There was no presence of GFP+ BMDCs at 24 hours, 48 hours, 4 days, and 7 days. Flow cytometry of the BM of GFP– mice demonstrated a constant increase in the presence of GFP+ BMDCs at 24 hours, 48 hours, and 4 days after BMT, which stabilized from 7 days to 7 weeks. Conclusions The study demonstrated the presence of GFP+ BMDCs in the dental pulp from 14 days to 7 weeks after BMT and the feasibility of using GFP+ animals and BMT as an in vivo model for tracking GFP+ BMDCs.