Comparison of Stem-cell-mediated Osteogenesis and Dentinogenesis

TLDR

The difference between stem‑cell‑mediated bone and dentin regeneration is not yet well‑understood. Here we use an in vivo stem‑cell transplantation system to investigate differential regulation mechanisms of bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs). Elevated expression of basic fibroblast growth factor (bFGF) and matrix metalloproteinase 9 (MMP‑9) was associated with hematopoietic marrow formation in BMSSC transplants but not in DPSC transplants, while dentin sialoprotein (DSP) specifically marked dentin synthesis in DPSC transplants and DPSCs were able to generate reparative dentin‑like tissue on human dentin surfaces, providing direct evidence that osteogenesis and dentinogenesis mediated by BMSSCs and DPSCs, respectively, are regulated by distinct mechanisms leading to different organization of mineralized and non‑mineralized tissues.

Abstract

The difference between stem-cell-mediated bone and dentin regeneration is not yet well-understood. Here we use an in vivo stem cell transplantation system to investigate differential regulation mechanisms of bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs). Elevated expression of basic fibroblast growth factor (bFGF) and matrix metalloproteinase 9 (MMP-9, gelatinase B) was found to be associated with the formation of hematopoietic marrow in BMSSC transplants, but not in the connective tissue of DPSC transplants. The expression of dentin sialoprotein (DSP) specifically marked dentin synthesis in DPSC transplants. Moreover, DPSCs were found to be able to generate reparative dentin-like tissue on the surface of human dentin in vivo. This study provided direct evidence to suggest that osteogenesis and dentinogenesis mediated by BMSSCs and DPSCs, respectively, may be regulated by distinct mechanisms, leading to the different organization of the mineralized and non-mineralized tissues.