Oscillatory equi-biaxial strain activates JNK in a frequency-dependent manner in bovine aortic endothelial cells

Cultured bovine aortic endothelial cells were subjected to either laminar fluid shear stress or equi-biaxial stretch. A step equi-biaxial stretch with an area increase of 25% resulted in a negligible increase in endogenous JNK1 kinase activity compared to cells in static condition. In contrast, a sinusoidal stretch with an area change from 0 to 25% resulted in a sustained increase in JNK1 activity up to 12 hr of stretch. Furthermore, the magnitude of activity varied directly with the frequency of oscillatory stretch in the range of 0.01 to 1 Hz. A step change in fluid shear stress from 0 to 16 dyn/cm² resulted in transient JNK1 activation which peaked at 60 min and returned to baseline levels after 12 hr of shear stress. A similar time course of JNK1 activation was observed upon application of shear stress with the amplitude oscillating between 0 and 16 dyn/cm² at a frequency of 1 Hz