Department of Operative Dentistry and Endodontics, Guanghua School and Hospital of Stomatology & Institute of Stomatological Research, Sun Yat-sen University, Guangzhou, China.
Int Endod J. 2012 Mar;45(3):224-33. doi: 10.1111/j.1365-2591.2011.01965.x. Epub 2011 Oct 12.
To investigate whether the p38α mitogen-activated protein kinases (MAPK) is involved in bone morphogenetic protein (BMP)-2-induced odontoblastic differentiation of human dental pulp cells (HDPCs).
Recombinant retrovirus encoding shRNA against p38α MAPK was constructed to investigate the role of p38α MAPK on BMP-2-induced odontoblastic differentiation of HDPCs. HDPCs were transfected with retrovirus expressing sh-p38α. Activation of p38α MAPK was detected by Western blot. The effects of p38α MAPK on BMP-2-induced odontoblastic differentiation of HDPCs were measured by alkaline phosphatase (ALP) activity, and the expression of odontoblastic markers was identified by quantitative real-time polymerase chain reaction analysis. The effect of SD-282, a p38a-specific inhibitor, on BMP-2-induced odontoblastic differentiation was also investigated.
BMP-2 dose- and time-dependently upregulated phosphorylation of p38α of HDPCs. Compared with BMP-2-treatment group, gene knock-down of p38α MAPK significantly inhibited ALP activity and the formation of mineralized nodules in HDPCs. Moreover, suppression of p38α MAPK repressed the odontoblastic differentiation in HDPCs. Consistently, inhibition of p38α by SD-282 also decreased odontoblastic differentiation.
p38α MAPK is involved in BMP-2-induced odontoblastic differentiation of HDPCs.
研究 p38α 丝裂原活化蛋白激酶（MAPK）是否参与骨形成蛋白-2（BMP-2）诱导的人牙髓细胞（HDPCs）成牙本质分化。
构建针对 p38α MAPK 的短发夹 RNA（shRNA）重组逆转录病毒，以研究 p38α MAPK 在 BMP-2 诱导的 HDPCs 成牙本质分化中的作用。HDPCs 用表达 sh-p38α 的逆转录病毒转染。通过 Western blot 检测 p38α MAPK 的激活情况。通过碱性磷酸酶（ALP）活性测定 p38α MAPK 对 BMP-2 诱导的 HDPCs 成牙本质分化的影响，通过定量实时聚合酶链反应分析鉴定成牙本质标志物的表达。还研究了 p38α 特异性抑制剂 SD-282 对 BMP-2 诱导的成牙本质分化的影响。
BMP-2 剂量和时间依赖性地上调 HDPCs 中 p38α 的磷酸化。与 BMP-2 处理组相比，p38α MAPK 的基因敲低显著抑制了 HDPCs 中的 ALP 活性和矿化结节的形成。此外，抑制 p38α MAPK 抑制了 HDPCs 中的成牙本质分化。一致地，SD-282 抑制 p38α 也降低了成牙本质分化。
p38α MAPK 参与 BMP-2 诱导的 HDPCs 成牙本质分化。
