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

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.