Hu Jiang-Tian, Li Yan, Yu Bing, Gao Guo-Jie, Zhou Ting, Li Song
Department of Orthodontics, School of Stomatology, Kunming Medical University, Kunming 650500, Yunnan, China.
Department of Orthodontics, School of Stomatology, Kunming Medical University, Kunming 650500, Yunnan, China.
Biochem Biophys Res Commun. 2015 Aug 21;464(2):493-9. doi: 10.1016/j.bbrc.2015.06.165. Epub 2015 Jul 7.
To explore how Girdin/GIV is regulated by cyclic tension and propagates downstream signals to affect cell proliferation and migration. Human osteoblast-like MG-63 cells were exposed to cyclic tension force at 4000 μstrain and 0.5 Hz for 6 h, produced by a four-point bending system. Cyclic tension force upregulated Girdin and Akt expression and phosphorylation in cultured MG-63 cells. Girdin and Akt each promoted the phosphorylation of the other under stimulated tension. In vitro MTT and transwell assays showed that Girdin and Akt are required for cell proliferation and migration during cellular quiescence. Moreover, STAT3 was determined to be essential for Girdin expression under stimulated tension force in the physiological condition, as well as for osteoblast proliferation and migration during quiescence. These findings suggest that the STAT3/Girdin/Akt pathway activates in osteoblasts in response to mechanical stimulation and may play a significant role in triggering osteoblast proliferation and migration during orthodontic treatment.
为探究Girdin/GIV如何受周期性张力调控并向下游传导信号以影响细胞增殖和迁移。将人成骨样MG-63细胞置于由四点弯曲系统产生的4000微应变和0.5赫兹的周期性张力下处理6小时。周期性张力上调了培养的MG-63细胞中Girdin和Akt的表达及磷酸化水平。在受刺激的张力下，Girdin和Akt相互促进对方的磷酸化。体外MTT和Transwell实验表明，在细胞静止期，Girdin和Akt是细胞增殖和迁移所必需的。此外，在生理条件下，受刺激的张力作用下，STAT3被确定为Girdin表达所必需，在静止期对成骨细胞增殖和迁移也至关重要。这些发现表明，STAT3/Girdin/Akt通路在成骨细胞中响应机械刺激而激活，可能在正畸治疗期间触发成骨细胞增殖和迁移中发挥重要作用。
