Unveiling and initial characterization of neural crest-like cells in mesenchymal populations from the human periodontal ligament.

OBJECTIVE: To identify cells with neural crest properties in mesenchymal populations isolated from human periodontal ligament.

BACKGROUND: Evidence from tracing experiments on animal embryos revealed proof that dental tissues are among the homing sites of craniofacial neural crest migratory cells. In humans, similar migratory cells were found in early embryos, but whether these cells are progeny of oral multipotent stem cells needs to be confirmed. Searching for the cells with neural crest characteristics in periodontal ligament mesenchymal populations can lead to a solution to the problem.

MATERIAL AND METHODS: Populations from the human periodontal ligament were cultured in media supplemented with various concentrations of fetal bovine serum (FBS); assays were performed to evaluate the expression of neural crest, mesenchymal and multipotency genes.

RESULTS: In periodontal ligament populations cultured in the standard expansion medium containing minimal amounts of FBS (0.5% or 1%) or lacking FBS, growing numbers of epithelial-like cells emerged, co-expressing neural crest-specific (p75, HNK-1, SOX10), the epithelialization (E-cadherin) and mesenchymal (CD73 and CD105) markers.

CONCLUSION: The human periodontal ligament contains a subpopulation of dormant neural crest-like cells, which can be highlighted by culturing at FBS concentrations below 2% or in a serum-free medium.