State Key Laboratory of Oral Disease, Sichuan University, West China School of Stomatology, Sichuan University, Chengdu, Sichuan, China.
J Endod. 2012 Sep;38(9):1207-13. doi: 10.1016/j.joen.2012.06.011. Epub 2012 Jul 20.
Hepatocyte growth factor (HGF) is a multifunctional cytokine that is able to stimulate multiple intracellular signaling pathways to induce a remarkable variety of biological activities in a wide spectrum of cell types. The functions of HGF in modulating diverse biological responses in mesenchymal stem cells have been reported, and our previous study also demonstrated that HGF exerts promoting functions on murine dental papilla cells. However, the potential mechanisms involved are not yet clearly understood. This study investigated the signaling pathway used by HGF in human dental papilla cells (hDPCs) to identify the role of mitogen-activated protein kinase (MAPK) pathways in inducing cell proliferation, differentiation, and migration.
The activation of P38 kinase and Jun N-terminal kinase (JNK) was analyzed by using specific antibodies against phospho-P38 and phospho-JNK. Proliferation of hDPCS was measured using the WST-8 assay with Cell Counting Kit-8, cell differentiation was determined by using alkaline phosphatase activity and mineralization assays, and migration was investigated by in vitro wound healing and transwell migration assays. Immunofluorescence staining was used to visualize fibrous actin (F-actin).
HGF activated JNK and P38 MAPK pathways in hDPCs. Blockage of JNK or P38 pathway in hDPCs significantly reduced cell proliferation, alkaline phosphatase activities, as well as mineral nodule formation induced by HGF. The JNK and P38 inhibitors also influenced F-actin remodeling stimulated by HGF and thus contributed to HGF-induced hDPCs migration.
Data from this study indicated that JNK and P38 MAPK pathways are required in HGF-induced biological responses in hDPCs.
肝细胞生长因子（HGF）是一种多功能细胞因子，能够刺激多种细胞内信号通路，在广泛的细胞类型中诱导多种生物学活性。HGF 在调节间充质干细胞中多种生物学反应的功能已被报道，我们之前的研究也表明 HGF 对鼠牙乳头细胞发挥促进作用。然而，其涉及的潜在机制尚不清楚。本研究探讨了 HGF 在人牙乳头细胞（hDPCs）中使用的信号通路，以确定丝裂原活化蛋白激酶（MAPK）通路在诱导细胞增殖、分化和迁移中的作用。
使用针对磷酸化 P38 和磷酸化 JNK 的特异性抗体分析 P38 激酶和 Jun N-末端激酶（JNK）的激活。使用 Cell Counting Kit-8 的 WST-8 测定法测量 hDPCS 的增殖，通过碱性磷酸酶活性和矿化测定法确定细胞分化，通过体外划痕愈合和 Transwell 迁移测定法研究迁移。免疫荧光染色用于可视化纤维状肌动蛋白（F-actin）。
HGF 激活了 hDPCs 中的 JNK 和 P38 MAPK 通路。在 hDPCs 中阻断 JNK 或 P38 通路显著降低了 HGF 诱导的细胞增殖、碱性磷酸酶活性以及矿化结节形成。JNK 和 P38 抑制剂也影响了 HGF 刺激的 F-actin 重塑，从而促进了 HGF 诱导的 hDPCs 迁移。
本研究的数据表明，JNK 和 P38 MAPK 通路是 HGF 诱导的 hDPCs 中生物学反应所必需的。
