Comparative Evaluation of Chemotactic Factor Effect on Migration and Differentiation of Stem Cells of the Apical Papilla

Introduction: Cell homing strategies could potentially be used in regenerative endodontic procedures (REPs) to promote the progressive corona! migration of stem cells, including stem cells of the apical papilla (SCAPs), along with formation of a new vascular network without the need for intentional apical trauma and intracanal bleeding. Although many chemotactic factors have been investigated for different mesenchymal stem cells, their effect on SCAP migration and differentiation is not fully understood. This study aimed to comparatively evaluate the effect of stromal cell derived factor 1 (SDF-1), transforming growth factor beta 1 (TGF-131), platelet-derived growth factor, granulocyte colony stimulating factor (G-CSF), or fibroblast growth factor 2 (FGF-2) on the migration and differentiation of SCAPs. Methods: A characterized SCAP cell line was fluorescently labeled with Vybrant DiO dye (Life Technologies, Grand Island, NY) and used in transwell migration assays. Cells were subjected to 1, 10, or 100 ng/mL of each factor or a combination of factors followed by detection in a fluorescent plate reader. Lastly, SCAP differentiation into a mineralizing phenotype was evaluated in the presence or absence of the tested factors by quantitative alizarin red staining and alkaline phosphatase activity. Data were analyzed with 1-way analysis of variance with the Tukey post hoc test. Results: Maximum migration was observed with G-CSF or FGF-2, which was significantly greater than the effects observed by the other tested factors. A combination of G-CSF with TGF-beta 1 significantly augmented both migration and differentiation into a mineralizing phenotype. Conclusions: G-CSF appears to be well suited to be further investigated as a key chemotactic factor in cell homing based regenerative endodontic procedures.