Confirmation of Existence of Three Types of Mesenchymal Progenitor Cells in Cultured Human Periodontal Ligament Cells

Abstract

The transplantation of ex vivo-expanded human periodontal ligament (HPL) cells or mesenchymal stem cell (MSC) -rich population isolated from the HPL cells with scaffolds into periodontal defects appears to be a powerful strategy to promote periodontal regeneration. However, up to date, there have been few direct evidences that each precursor of various mesenchymal cell types and MSC exist in the heterogeneous HPL cell cultures. In this study, we qualitatively estimated a potential to differentiate into three types of mesenchymal cells in the HPL cells, as compared with that in human bone marrow-derived MSC (HMSC), which were used as a control. As results, the HPL cells contained many osteoblast lineage cells and small number of adipocyte precursors, while chondrocyte precursors might exist at slight levels or not in the cells. Further, alkaline phosphatase (ALP) negative cell-rich (ALP^Low) fraction isolated from the HPL cells contained relatively more adipocyte precursors.