Electrically stimulated induction of hsp70 gene expression in mouse astroglia and fibroblast cells

Mouse astroglial cells, which were cultured on an electrode, were found res ponsive to an electric stimulation of sine wave potential in enhancing hsp7 0 mRNA resulting from an activation of hsp70 gene expression. On the basis of this finding, electrically responsive cells were established by transfec ting mouse 3T3-L1 cells with a constructed plasmid encoding hsp70 promoter and the firefly luciferase gene. A stable cell line has been established th rough selection of heat-stimulated luciferase expression. A 1-h electric st imulation of the cells resulted in activation of luciferase expression, whi ch was confirmed to produce an increase in light emission. The sequential p attern of the electrically stimulated expression of luciferase was found di fferent from that of the heat stimulation. Furthermore, the promoter was ac tivated depending on the potential and duration of the stimulation applied. Consequently, the electric stimulation has proven effective on activating hspP70 promoter. This cell line is feasible in expressing the gene of inter est by electrical stimulation, which lead us to construct environment respo nsive cells in general. (C) 2000 Elsevier Science B.V. All rights reserved.