Human neural crest-derived postnatal cells exhibit remarkable embryonic attributes either in vitro or in vivo

During human embryonic development, odontogenic tissues, deriving from the neural crest, remain undifferentiated until the adult age. This study was aimed at characterising the cells of the follicle enveloping the dental germ, due to its direct origin from neural crests. Sixty dental follicles were collected from patients aged 18 to 45 years. This research has clarified that dental follicles, if extracted in a very early stage, when dental roots did not start to be formed, contain a lineage of cells, characterised by a high degree of plasticity in comparison with other adult stem cell populations. In particular, we found that these cells share the following features with ES: (i) high levels of embryonic stem cell markers (CD90, TRA1-60, TRA1-81, OCT-4, CD133, and SSEA-4); (ii) mRNA transcripts for Nanog and Rex-1; (iii) broader potency, being able to differentiate in cell types of all three germ layer, including smooth and skeletal muscle, osteoblasts, neurons, glial cells, and adipocytes; (iv) high levels of telomerase activity; (v) ability to form embryoid bodies; (vi) ability, after injection in murine blastocysts, to be localised within the inner cell mass; (vii) no teratoma formation after injection; (viii) in vivo tissue formation after transplantation. Our results demonstrate that these cells represent a very easy accessible and extraordinary source of pluripotent cells and point out the fact that they own the cardinal feature of embryonic stem cells.