UCLA

DPSCs, also known as, dental pulp stem cells, were the first human dental mesenchymal stem cells (MSCs) to be identified from pulp tissues. DPSCs and their classification as mesenchymal stem cells is an attractive target for clinical applications in dentistry. DPSCs have been shown to differentiate into odontoblasts/osteoblasts, chondrocytes, and adipocytes. While studying a rare genetic disorder, Fan et al was able to uncover BCOR, a complex in which mutation could have intrinsic effect on the function of MSCs from the root apical papilla. One of the members of the BCOR complex is polycomb group ring finger 1 (PCGF1). PCGF1 is also a member of the polycomb group repressive complex 1 (PRC1). Due to its membership in repressive complexes, BCOR and PRC1, and its role in development, in this study we decided to investigate the role of PCGF1 in DPSC odontogenic differentiation. In order to evaluate the role of PCGF1 in DPSCs, we used small interfering RNA to silence the PCGF1 gene and observe the changes in our DPSC population. We found that after PCGF1 knockdown and treatment with odontogenic/osteogenic inducing media, mineralized nodule formation and odontogenic potential decreased, suggesting that PCGF1 plays a role in the odontogenic lineage commitment of DPSCs. We also found that mechanistically, PCGF1 blocks inhibition of developmental genes MSX1/MSX2 and DLX2/DLX5 in order to facilitate the odontogenic lineage commitment of DPSCs. Taken together, this study might shed light on the potential therapeutic implications of exploiting this pathway in DPSCs.