OBJECTiVES: The angiogenic potential of human dental pulp stem cells (DPSCs) was investigated by in vitro differentiation experiments.
METHODS: Dental pulp-derived cells were characterized for a set of mesenchymal-specific antigens by flow cytometry. The differentiation potential of these cells was assessed in vitro by osteogenic (von Kossa stain), adipogenic (Oil Red-O stain) and chondrogenic (pellet culture) inductions. After exposure to Vascular Endothelial Growth Factor (VEGF) the angiogenic commitment was evaluated by in vitro functional assays and by flow cytometry for endothelial markers expression.
RESULTS: The adherent cells isolated from dental pulp were homogenously positive to the typical mesenchymal markers (CD105 ,CD73, CD29, CD166), and negative for the hematopoietic markers CD14, CD34, CD45. The cells displayed osteogenic and adipogenic potential. In angiogenic experiments, a differentiation into endothelial cells was detected by in vitro matrigel assay; this behaviour was enhanced by VEGF induction. In accordance with these findings, VEGF receptor 1 and 2 (FLT-1 and KDR) were basally expressed in DPSCs and the expression of endothelial-specific markers like FLT-1, KDR, ICAM-1 increased after exposure to VEGF together with the occurrence of CD34 and von Willebrand Factor positive cells.
CONCLUSION: Dental pulp, a tissue usually discarded, is a very attractive high-yield multipotent stem cell source, free of ethical conflicts, that may open new possibilities for clinical applications. In particular, the angiogenic potential of DPSCs may allow new therapeutic approaches, based on tissue-engineered vascular grafts, for the treatment of various forms of vascular diseases.