Effects of mechanical strain on expression of ERK1/2 in osteoblastic cells in vitro
CAO Yang1, ZHENG Yi2, CHEN Yang-Xi3, LUO Song-Jiao31Department of Orthodontics,Guanghua College of Stomatology, Sun Yat-sen University, Guangzhou 510055, China, 2Smile Research Center of Stomatology, Zhuhai 519000, China, 3Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
AIM: To study the effect of mechanical strain on the expression of ERK1/2 in osteoblast-like cells in vitro. METHODS: Osteoblast-like cells were cultured and then subjected to mechanical strain by self-made four-point bending system at a 0.5 Hz frequency for 5, 15, 30 min, 1, 3, 6 h, respectively. In each time-phase, the cells were loaded with tension and compression stress at 4000 μ strain respectively. The phosphorylation levels of ERK1/2 were measured by Western Blot. Changes in the experiments were expressed as ratio to the controls. RESULTS: The self-made four-point bending system supplied an accurate and effective cyclic uniaxial strain to the cultured adhesion cells in vitro. 4000 μ strain tension stimulus and compress stimulus induced the expression of ERK in a few minutes and the effect of tension strain was more significant (P0.05). It may be due to the distinct mechanotransductive mechanism of the different directional mechanical strain. CONCLUSION: Mechanical strain plays an important role in the activation of signaling pathway of MAPK/EPK in osteoblasts . The effect of tension strain is more significant than compress strain. Mechanical strain is involved in the activation of extracellular signal regulated kinase.