• Mechanical strain;
  • Mechanotransduction;
  • NF-κB;
  • Osteoblast


This study was to examine the early responses of nuclear factor kappa B (NF-κB) to mechanical strains in MG-63. MG-63 cells were subjected to cyclic uniaxial compressive or tensile strain, produced by a four-point bending system, at 1000 μstrain or 4000 μstrain for 5 min, 15 min, 30 min and 1 h, respectively. Control cells received the same treatment with no mechanical stress loading. Expression of NF-κB (p60) was measured by Western blotting. NF-κB responded rapidly to mechanical stimuli in MG-63 cells. NF-κB was activated by cyclic uniaxial stretch at 1000 μstrain while it was restrained under a compressive strain environment at 1000 μstrain (P < 0.001). The effects reversed for tension and compression at 4000 μstrain (P < 0.001). Furthermore, strains at 1000 μstrain affected NF-κB expression much easier than those at 4000 μstrain. This indicates that there may be different responding mechanisms or mechanotransduction pathways for different mechanical stimuli.