Yin Jian, Hao Zhichao, Ma Yuanyuan, Liao Shuang, Li Xianxian, Fu Jing, Wu Yeke, Shen Jiefei, Zhang Ping, Li Xiaoyu, Wang Hang
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu, 610041, China.
Cell Biol Int. 2014 May;38(5):591-8. doi: 10.1002/cbin.10235. Epub 2014 Jan 10.
IL-6 has a dual role in bone remodelling. The ERK1/2 pathway partially upregulated IL-6 secretion in osteocyte-like MLO-Y4 cells exposed to CCF. We have now investigated the possible role of phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway in the CCF-induced IL-6 expression. MLO-Y4 cells were treated with CCF 2,000 µstrain, 2 Hz, or 10, 30 min, 1, 3 and 6 h. IL-6 expression, Akt and ERK1/2 and PI3K/Akt phosphorylation were determined by RT-PCR, ELISA and Western blotting. Inhibition of PI3K/Akt with LY294002 or ERK1/2 with PD98059 significantly attenuated IL-6 upregulation, and IL-6 expression was abolished by inhibiting both pathways. Inhibition of one pathway downregulated the other's phosphorylation level. In conclusion, concomitant activation of PI3K/Akt and ERK1/2 pathways mediated IL-6 expression in MLO-Y4 cells under CCF.
白细胞介素-6在骨重塑中具有双重作用。细胞外钙流（CCF）作用下，细胞外信号调节激酶1/2（ERK1/2）通路部分上调了骨细胞样MLO-Y4细胞中白细胞介素-6的分泌。我们现在研究了磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B（Akt）信号通路在CCF诱导的白细胞介素-6表达中的可能作用。用2000微应变、2赫兹的CCF处理MLO-Y4细胞，处理时间为10、30分钟以及1、3和6小时。通过逆转录聚合酶链反应（RT-PCR）、酶联免疫吸附测定（ELISA）和蛋白质免疫印迹法检测白细胞介素-6的表达、Akt、ERK1/2以及PI3K/Akt的磷酸化水平。用LY294002抑制PI3K/Akt或用PD98059抑制ERK1/2均显著减弱白细胞介素-6的上调，同时抑制这两条通路可消除白细胞介素-6表达。抑制一条通路会下调另一条通路的磷酸化水平。总之，在CCF作用下，PI3K/Akt和ERK1/2通路的协同激活介导了MLO-Y4细胞中白细胞介素-6的表达。
