과잉치 치주인대 줄기세포의 특성

Abstract

Human teeth have been identified as a new source of postnatal stem cells that have the capacities of selfrenewal and multilineage differentiation. In this study we compared the characteristics of stem cells obtained from the periodontal ligament of supernumerary teeth (sPDLSCs) with those of bone-marrow-derived mesenchymal stem cells (BMMSCs), with the aim of extending the sources of stem cells. We performed a colony forming unit-fibroblast (CFU-F) assay to evaluate the self-renewal ability of the cells. Reverse transcription-polymerase chain reaction (RTPCR) and flow cytometry analyses were used to detect the expressions of various stem-cell markers: Oct-4, Nanog, Nestin, Stro-1, CD146, CD105, CD29, CD44, CD90 and CD31. The abilities of adipogenic and osteogenic differentiation were monitored by histochemical staining and quantitative RT-PCR. The colony-forming efficiency was slightly higher for sPDLSCs than for BMMSCs (6.0% vs. 5.1%, respectively). The two stem cell populations expressed similar stem-cell markers except Nestin, Stro-1, and CD146. The sPDLSCs could differentiate to adipogenic lineage; however, the up-regulation of peroxisome-proliferator-activated receptor γ2 (PPARγ2) and lipoprotein lipase (LPL) gene expressions was less than for the BMMSCs. Osteogenic differentiation of the sPDLSCs was confirmed by up-regulation of alkaline phosphatase (ALP) and bone sialoprotein (BSP) gene expressions, but elevation of ALP gene expression was observed earlier than for the BMMSCs. We have shown that sPDLSCs exhibit stem-cell properties such as self-renewal ability, expression of stem-cell markers, and differentiation into adipogenic and osteogenic lineages. This cell type could represent a good stem-cell candidate for use in regenerative medicine.