JNK MAPK is involved in BMP-2-induced odontoblastic differentiation of human dental pulp cells
JNK MAPK is involved in BMP-2-induced odontoblastic differentiation of human dental pulp cells
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DOI：
10.3109/03008207.2014.882331
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发表时间：
2014-06-01
影响因子：
2.9
通讯作者：
Lin, Zhengmei
中科院分区：
文献类型：
--
作者：
Qin, Wei;Liu, Pengcheng;Lin, Zhengmei
骨形态发生蛋白-2 (BMP-2) 是一种多功能生长因子，属于转化生长因子 β 超家族，具有广泛的活性，可影响许多不同的细胞类型。 BMP-2 可诱导人牙髓细胞 (DPC) 向成牙本质细胞分化，但其潜在机制仍不清楚。在这项研究中，我们研究了 JNK 丝裂原激活蛋白激酶 (MAPK) 通路在 BMP-2 诱导的 DPC 成牙本质细胞分化中的潜在作用。用 BMP-2 和 JNK 抑制剂 SP600125 处理后，通过蛋白质印迹分析对磷酸化和非磷酸化 JNK MAPK 的水平进行定量。通过测量碱性磷酸酶 (ALP) 活性并使用定量实时聚合酶链反应分析检查成牙本质细胞标记物的表达，确定 JNK MAPK 在 BMP-2 诱导的 DPC 成牙本质细胞分化中的作用。还研究了 JNK MAPK 沉默对成牙本质细胞分化的影响。 BMP-2 以剂量和时间依赖性方式上调 DPC 中 JNK 的磷酸化。 JNK 抑制剂不会抑制成牙本质细胞分化的早期标志物，包括 ALP 活性、骨桥蛋白和牙本质基质蛋白-1。然而，JNK抑制剂SP600125显着抑制成牙本质细胞的后期分化，包括骨钙素、牙本质唾液磷蛋白和骨唾液蛋白的基因表达，并且还减少了BMP-2处理的DPC中矿化结节的形成。与这一观察结果一致，JNK MAPK 的沉默也减少了晚期成牙本质细胞的分化。总而言之，这些发现表明 JNK 活性是 BMP-2 诱导的晚期成牙本质细胞分化所必需的。
Bone morphogenetic protein-2 (BMP-2) is a multi-functional growth factor belonging to the transforming growth factor beta superfamily that has a broad range of activities that affect many different cell types. BMP-2 induces odontoblastic differentiation of human dental pulp cells (DPCs), but the underlying mechanism remains unclear. In this study, we investigated the potential role of the JNK mitogen-activated protein kinases (MAPK) pathway in BMP-2-induced odontoblastic differentiation of DPCs. The levels of phosphorylated and unphosphorylated JNK MAPK were quantified by Western blot analysis following treatment with BMP-2 and the JNK inhibitor SP600125. The role of JNK MAPK in the BMP-2-induced odontoblastic differentiation of DPCs was determined by measuring alkaline phosphatase (ALP) activity and by examining the expression of odontoblastic markers using quantitative real-time polymerase chain reaction analysis. The effect of JNK MAPK silencing on odontoblastic differentiation was also investigated. BMP-2 upregulated the phosphorylation of JNK in DPCs in a dose-and time-dependent manner. Early markers of odontoblastic differentiation, including ALP activity, osteopontin and dentin matrix protein-1, were not inhibited by the JNK inhibitor. However, the JNK inhibitor, SP600125, significantly inhibited late-stage differentiation of odontoblasts, including the gene expression of osteocalcin, dentin sialophosphoprotein and bone sialoprotein, and also reduced the formation of mineralized nodules in BMP-2-treated DPCs. Consistent with this observation, silencing of JNK MAPK also decreased late-stage odontoblastic differentiation. Taken together, these findings suggest that JNK activity is required for late-stage odontoblastic differentiation induced by BMP-2.