Fang Qingqing, Li Zhizhong, Zhou Jian, Yan Juanli, Shi Wengui, Xie Yanfang, Chen Keming
Institute of Orthopaedics, Lanzhou General Hospital of Chinese PLA, Lanzhou Gansu, 730050, P. R. China.
College of Life Science and Engineering, Lanzhou University of Technology.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2016 Oct 8;30(10):1238-1243. doi: 10.7507/1002-1892.20160253.
To investigate whether signal molecule mitogen-activated protein kinases (MAPKs) involves in the process of the mineralization and maturation of rat calvarial osteoblasts promoted by 50 Hz, 0.6 mT pulsed electromagnetic fields.
Rat calvarial osteoblasts were obtained by enzyme digestion from the skull of 6 neonatal Wistar rats of SPF level. The primary osteoblasts were treated in 50 Hz and 0.6 mT pulsed electromagnetic fields for 0, 5, 10, 20, 40, 60, and 120 minutes; the protein expression of phosphorylated MAPKs was detected by Western blot. The osteoblasts were randomly divided into group A (control group), group B (low frequency pulse electromagnetic fields treatment group), group C (SB202190 group), and group D (SB202190+low frequency pulse electromagnetic fields treatment group); the alkaline phosphatase (ALP) activities were tested after corresponding treatment for 1, 4, and 7 days. The corresponding treated more than 90% confluenced osteoblasts were cultured under condition of osteogenic induction, then ALP staining and alizarin red staining were carried out at 9 and 12 days respectively.
The results of Western blot showed that there was no significant changes in the protein expressions of phosphorylated level of extracellular signal-related kinases 1/2 and c-Jun amino N-terminal kinases 1/2 in 50 Hz, 0.6 mT pulsed electromagnetic fields >0.05), but the phosphorylated level of p38 began to increase at 5 minutes, peaked at 40 minutes, then gradually decreased, and it was significantly higher at 5-120 minutes than at 0 minute (<0.05). After the activities of p-p38 was inhibited by inhibitor SB202190, the ALP activities, positive colonies and area of ALP and calcified nodules of group B were significantly higher than groups A, C, and D (<0.05).
p38 is one of the signal molecules involved in the process of the mineralization and maturation of rat calvarial osteoblasts promoted by 50 Hz, 0.6 mT pulsed electromagnetic fields.
探讨信号分子丝裂原活化蛋白激酶（MAPKs）是否参与50Hz、0.6mT脉冲电磁场促进大鼠颅骨成骨细胞矿化及成熟的过程。
采用酶消化法从6只SPF级新生Wistar大鼠颅骨获取大鼠颅骨成骨细胞。原代成骨细胞分别在50Hz、0.6mT脉冲电磁场中处理0、5、10、20、40、60和120分钟；采用蛋白质免疫印迹法检测磷酸化MAPKs的蛋白表达。将成骨细胞随机分为A组（对照组）、B组（低频脉冲电磁场处理组）、C组（SB202190组）和D组（SB202190+低频脉冲电磁场处理组）；相应处理1、4和7天后检测碱性磷酸酶（ALP）活性。将相应处理后汇合度超过90%的成骨细胞在成骨诱导条件下培养，分别在9天和第12天进行ALP染色和茜素红染色。
蛋白质免疫印迹结果显示，50Hz、0.6mT脉冲电磁场作用下，细胞外信号调节激酶1/2和c-Jun氨基末端激酶1/2磷酸化水平的蛋白表达无明显变化（P>0.05），但p38磷酸化水平在5分钟开始升高，40分钟达到峰值，随后逐渐下降，5-120分钟时显著高于0分钟（P<0.05）。用抑制剂SB202190抑制p-p38活性后，B组的ALP活性、阳性集落数以及ALP和钙化结节面积均显著高于A组、C组和D组（P<0.05）。
p38是50Hz、0.6mT脉冲电磁场促进大鼠颅骨成骨细胞矿化及成熟过程中的信号分子之一。
