The effects of mechanical vibration on cellular health in differentiated neuroblastoma cells

The effects of mechanical impact forces on neurological health is a critical concern, likely due to issues of traumatic brain injury (TBI) in sports and brain damage stemming from the potential of "sonic terrorism." The quantitative analysis and evaluation of such forces on brain tissue function is very difficult. To address this issue, this research proposes a novel approach of using a cellular model subjected to mechanical vibration for analysis. Here, neuron-like differentiated neuroblastoma cells were subjected to vibration at frequencies of 20, 200, 2000, and 20000 Hz for a period of 24 hours at constant amplitude. Cell proliferation and inflammatory cytokine production, including IL-6, IL-1β, and TGF-β1, was measured as response of the cells and indicators of cellular health after vibrational treatment. Cell proliferation was found to increase after 20, 200, and 20000 Hz treatments; p<0.05) and decrease after 2000 Hz treatment (p<0.05). IL-6 production was found to decrease after 200 and 20000 Hz treatments (p<0.01) and increase after 20 and 2000 Hz treatments (p<0.01). IL-1β protein production was found to decrease after 20 Hz and increase after 200 Hz treatments (p<0.001), while TGF-β1 was found to decrease after 200 Hz treatment (p<0.001). The results suggest that cell proliferation and cytokine production serve as a sensitive measure to external impact forces applied to the cells. In addition, it is suggested that inflammatory mechanisms exhibit inhibitory "cross-talk" between IL-6 and IL-1β signaling pathways at 20 and 200 Hz. Inflammatory cytokine data suggest frequency-specific responses, which can be used not only to better understand the mechanism of vibration induced cellular damage, but also to unveil the cellular signaling processes.