結合組織増殖因子CTGF/CCN2が歯胚間葉細胞の象牙芽細胞分化に与える影響 Effects of connective tissue growth factor (CTGF/CCN2) on the differentiation of tooth germ mesenchymal cells into odontoblasts
Recent studies using novel bioengineering techniques have demonstrated the regeneration of mammalian dental tissues from tooth-derived cells. In this study, we established a novel in vitro culture system with the use of undifferentiated dental mesenchymal cells from bovine bell-staged tooth germs and promoted differentiation of these cells into functioning odontoblasts. During the. 21-day culture period, the dental mesenchymal cells were exposed to 5 μg/ml ascorbic acid and 1 mM β-glycerophosphate (β-GP). These undifferentiated mesenchymal cells exhibited characteristics of odontoblasts at all stages of differentiation, starting from the immature stage to the terminal mineralization stage. Connective tissue growth factor (CTGF/CCN2) is a potent growth factor that regulates proliferation and differentiation of both chondrocytes and osteoblasts. Since CTGF is also expressed in differentiating preodontoblasts, we examined if CTGF can promote odontoblast differentiation. Recombinant CTGF (rCTGF), in the presence of ascorbic acid and β-GP, stimulated the expressions of the early odontoblast differentiation marker alkaline phosphatase (ALP) and collagen type I mRNA. In addition, the maturation markers osteopontin and dentin sialophosphoprotein (DSPP) mRNA were also expressed during the 9-day culture period. Histological and histochemical analyses confirmed that rCTGF, in the presence of ascorbic acid and β-GP, stimulated high alkaline phosphatase activity, calcium incorporation, and hydroxyapatite deposition. These findings demonstrated that our novel culture system can maintain the osteogenic potential of undifferentiated dental mesenchymal cells and promote their differentiation into functional odontoblasts. Furthermore, rCTGF is capable of promoting the differentiation of tooth germ mesenchymal cells into odontoblasts, suggesting that CTGF may be therapeutically useful in the future for promoting tooth regeneration.
日本口腔外科学会雑誌 52(5), 271-278, 2006-05-20
Japanese Society of Oral and Maxillofacial Surgeons