Department of Conservative Dentistry, Wonkwang University School of Dentistry, Iksan, Korea.
J Endod. 2013 Jan;39(1):76-82. doi: 10.1016/j.joen.2012.10.013. Epub 2012 Nov 10.
We previously reported that simvastatin and enamel matrix derivative (EMD) have a dentinogenic effect. However, there is little information about the combined effects of these 2 agents on odontoblastic differentiation. The aim of this study was to investigate the effects of combined treatment with simvastatin and EMD on odontoblastic differentiation of human dental pulp cells (hDPCs). This study further explored the role of extracellular signal-regulated kinase (ERK) as a target and mediator of the differentiation induced by simvastatin in hDPCs.
The odontoblastic differentiation was analyzed by alkaline phosphatase activity, real-time polymerase chain reaction (PCR) for odontoblastic/osteoblastic markers (ie, dentin sialophosphoprotein, dentin matrix protein 1, and osteonectin), and alizarin red S staining. We also explored the role of ERK signaling as a mediator of simvastatin by Western blotting and real-time PCR. The expression of osteoblast-specific transcription factors was detected by reverse-transcription PCR.
The alkaline phosphatase activity and the expression of odontoblastic markers (ie, dentin sialophosphoprotein and dentin matrix protein 1) increased in simvastatin/EMD-treated cells. Mineralized nodule formation increased in EMD- and simvastatin/EMD-treated cells. Notably, the combined use of both simvastatin and EMD resulted in more potent differentiation than that observed after a single therapy. Simvastatin activated ERK phosphorylation and treatment with ERK inhibitor blocked the messenger RNA expression of odontoblastic markers. However, in simvastatin/EMD-treated cells, the expression of these genes did not decrease significantly. Compared with other groups, the EMD- and simvastatin/EMD-treated group showed a greater expression of osterix.
Simvastatin promotes odontoblastic differentiation of hDPCs via the ERK signaling pathway. In addition, simvastatin-induced differentiation is facilitated by co-treatment with EMD. Collectively, these results suggest a new strategy to induce odontoblastic differentiation of hDPCs.
我们之前报道过辛伐他汀和釉基质衍生物（EMD）具有成牙本质作用。然而，关于这两种药物联合作用对成牙本质细胞分化的影响的信息较少。本研究旨在探讨辛伐他汀和 EMD 联合治疗对人牙髓细胞（hDPC）成牙本质分化的影响。本研究进一步探讨了细胞外信号调节激酶（ERK）作为辛伐他汀诱导 hDPC 分化的靶标和介质的作用。
通过碱性磷酸酶活性、牙本质涎磷蛋白、牙本质基质蛋白 1 和骨桥蛋白等牙本质/成骨标志物的实时聚合酶链反应（PCR）分析牙本质分化，茜素红 S 染色。我们还通过 Western blot 和实时 PCR 探讨了 ERK 信号作为辛伐他汀介导物的作用。通过逆转录 PCR 检测成骨特异性转录因子的表达。
在辛伐他汀/EMD 处理的细胞中，碱性磷酸酶活性和牙本质标志物（即牙本质涎磷蛋白和牙本质基质蛋白 1）的表达增加。在 EMD 和辛伐他汀/EMD 处理的细胞中，矿化结节形成增加。值得注意的是，两种药物的联合使用比单一治疗产生更强的分化作用。辛伐他汀激活 ERK 磷酸化，ERK 抑制剂治疗阻断牙本质标志物的信使 RNA 表达。然而，在辛伐他汀/EMD 处理的细胞中，这些基因的表达并没有显著下降。与其他组相比，EMD 和辛伐他汀/EMD 处理组的osterix 表达更高。
辛伐他汀通过 ERK 信号通路促进 hDPCs 的成牙本质分化。此外，EMD 联合辛伐他汀诱导的分化促进了 hDPCs 的成牙本质分化。综上所述，这些结果为诱导 hDPCs 成牙本质分化提供了一种新策略。
