Insulin-like growth factor-1 promotes the proliferation and odontogenic differentiation of human dental pulp cells in vitro and in vivo.

Abstract

Human dental pulp cells (hDPCs) have emerged as a potential alternative for the regeneration of dental tissues. Insulin-like growth factor-1 (IGF-1) is involved in the proliferation and osteogenic differentiation of hDPCs in vitro. However, the effect of IGF-1 on the proliferation and odontogenic dif-ferentiation of hDPCs in vivo remains unknown. This study collected hDPCs from healthy premolars and third molars by collagenase type I and dispase. Immunocytochemical staining showed positive vimentin staining and negative cytokeratin staining in hDPCs. Treatment with IGF-1 (50, 75, and 100 ng/mL) significantly increased the proliferation ability of hDPCs in a concentration-de-pendent manner. In vivo experiments, hDPCs were seeded into an acellular der-mal matrix and transplanted subcutaneously into nude mice. After two and four weeks of transplantation, the hematoxylin and eosin staining revealed more cells and extracellular matrix in implants from the IGF-1 treatment group, and Alizarin Red staining revealed more mineralized tissue compared to the control group. Transmission electron microscopy (TEM) analysis of hDPCs showed an abundance of mitochondria, rough endoplasmic reticulum, and Golgi complex-es. In conclusion, IGF-1 promotes the proliferation of hDPCs in vitro and odon-togenic differentiation of hDPCs in vivo, indicating that modifying IGF-1 signal-ing may provide potential strategies for the regeneration of dental tissues.