Characterization of Mesenchymal Stem Cells Derived from Periodontal Ligament

It is well-known that mesenchymal stem cells responsible for periodontal tissue regeneration exist in the periodontal ligament by differentiation into fibroblasts, cementoblasts, and osteoblasts. However, the detailed characteristics of stem cells have not been clarified. Recently, the presence of a novel stem cell called Muse cells has been reported. It was mentioned that Muse cells exist in all mesenchymal tissues, and which can be found in the bone marrow, skin and adipose tissues. Nevertheless, the existence of Muse cells in oral tissues has not yet been reported. This study investigated whether Muse cells are present in the periodontal ligament. Results showed that about 0.83% of Muse cells sorted out from periodontal ligament cells showed the ability for self-renewal as well as the expression of genes present in all three germ layers. When compared to Muse cells derived from the skin for calcification ability, Muse cells derived from periodontal ligament showed higher calcification ability both at gene and tissue levels. Although both cells were considered Muse cells, cells derived from the periodontal ligament have different characteristics compared to the Muse cells derived from the skin. The results suggest that stem cells derived from somatic cells are possible to maintaining the original phenotypes. Therefore, when using stem cells for regenerative medicine, we suggest that the stem cells should be sorted from the same tissue, which expects repair or regeneration of the tissue.