New development of the regeneration ofpulp-dentin complex by FGF-2

一些证据表明，间充质干细胞存在于牙髓组织中。这使我们推测，适当的激活牙髓细胞能够诱导牙本质-牙髓复合体的再生，而牙本质-牙髓复合体已被创伤或龋齿破坏。在我们之前的研究中，我们发现FGF-2刺激牙周韧带细胞诱导牙周组织再生。在本研究中，我们检测了FGF-2对人牙髓细胞的生物学效应。人类牙髓细胞是从接受拔牙正畸治疗的个体第一前磨牙的健康牙髓组织中分离出来的。在存在或不存在重组人FGF-2的情况下培养体外维持的人牙髓细胞。RT-PCR检测细胞中胶原蛋白、层粘连蛋白和透明质酸合成酶mRNA的表达，ELISA检测培养上清液中透明质酸的浓度。FGF-2对细胞增殖反应的影响通过3^[H]-胸腺嘧啶摄取测定。我们证实了FGF-2增加了人牙髓细胞的增殖反应。此外，RT-PCR结果显示，FGF-2增加了□3层粘连蛋白、透明质酸合酶- 1,2 mRNA的表达，但降低了I型胶原mRNA的表达。此外，我们发现FGF2诱导髓细胞的透明质酸合成。这些结果表明，FGF-2调节髓细胞产生细胞外基质，在髓组织伤口愈合过程中起重要作用。

Several lines of evidence demonstrated that mesenchymal stem cells exist within dental pulp tissues. This allows us to speculate that appopriate activation of dental pulp cells enable to induce regeneration of dentin-pulp complex which has been destroyed by trauma or dental caries. In our previous studies, we revealed that FGF-2 stimulates periodontal ligament cells to induce periodontal tissue regeneration.In this study, we examined biological effects of FGF-2 on human pulp cells. Human pulp cells were isolated from healthy pulp tissues of first premolar teeth of individuals undergoing tooth extraction for orthodontic treatment. The in vitro maintained human pulp cells were cultured in the presence or absence of recombinant human FGF-2. Expressions of collagen, laminin- and hyaluronan synthase mRNA in the cells were examined by RT-PCR analysis Concentration of hyaluronan in the culture supernatants were measured by ELISA. Effects of FGF-2 on proliferative responses of the cells were determined by 3^[H]- thymidine uptake. We confirmed that FGF-2 increased proliferative responses of human pulp cells. In addition, RT-PCR revealed that FGF-2 increased expression of □3 laminin, hyaluronan synthase-1, 2 mRNA, but decreased Type I collagen mRNA. Furthermore, we found that FGF2 induced hyaluronan synthesis of the pulp cells. These results indicate that FGF-2 regulates extracellular matrix production by pulp cells, that play important roles in wound healing process of pulp tissues.