The precursor osteoblast-like cell, MC3T3-E1 cell line, enhances sodium–calcium exchanger 1 (Ncx1) gene expression by stretch stimuli prior to osteoblast differentiation

This study evaluated the expression of genes involved in the concentration of Ca(2+) in precursor osteoblast-like cell, MC3T3-E1 subjected to stretching stimuli. Transient receptor potential vanilloid 4 (Trpv4) gene expression, the factor that is activated by stretch stimulation and enables inflow of Ca(2+) from the extracellular space, was not affected as a result of stretch stimulation; conversely, the expression of sodium-calcium exchanger 1 (Ncx1) gene involved in outflow of intracellular Ca(2+) increased, depending on stimulation intensity. Localization of Ca(2+) correlated with the positioning of the endoplasmic reticulum, and intracellular Ca(2+) decreased in inverse proportion to the intensity of the stretching force. These results suggest that stretch stimulation activates intracellular Ca(2+) elimination rather than Ca(2+) uptake before osteoblast differentiation.