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

多条证据表明间充质干细胞存在于牙髓组织中。这使得我们可以推测，牙髓细胞的凋亡性激活能够诱导牙本质-牙髓复合体的再生，这些复合体已经被创伤或龋齿破坏。在我们以前的研究中，我们发现成纤维细胞生长因子-2刺激牙周韧带细胞诱导牙周组织再生。在本研究中，我们检测了成纤维细胞生长因子-2对人牙髓细胞的生物学作用。从拔牙患者第一前磨牙健康牙髓组织中分离出人牙髓细胞，用于正畸治疗。体外培养的人牙髓细胞在有或没有重组人成纤维细胞生长因子-2的情况下培养。RT-PCR法检测细胞胶原、层粘连蛋白和透明质酸合成酶mRNA的表达，酶联免疫吸附试验检测细胞培养上清液中透明质酸的浓度。用3^[H]-胸腺嘧啶核苷摄取率测定成纤维细胞生长因子-2对细胞增殖反应的影响。我们证实了成纤维细胞生长因子-2增强了人牙髓细胞的增殖反应。RT-PCR结果显示，成纤维细胞生长因子-2促进层粘连蛋白-3、透明质酸合成酶-1、2mRNA的表达，下调I型胶原的表达。此外，我们还发现FGF2诱导牙髓细胞合成透明质酸。这些结果表明，成纤维细胞生长因子-2调节牙髓细胞产生细胞外基质，在牙髓组织创面愈合过程中发挥重要作用。

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.