Genome-Wide Gene Expression Analysis of NIH 3T3 Cell Line Under Mechanical Stimulation

Cyclic mechanical stretching induces biological and biomechanical response in cells. These responses are firstly determined by gene expression regulation in the cells of tissue. A method based on the CellDrum (R) Technology provided the environment for cyclic mechanical stimulation of NIH 3T3 cells in vitro. Cells were cultured on a silicone membrane. mRNA expression levels of the genes Egr1, Fgfr2, Tp53, Itgb3, and Itgb5 was evaluated by real-time PCR at stimulation times ranging from 5 min to 12 h with a cyclic strain of 0.25% at 0.25 Hz in order to decide which time period was most suitable for a subsequent detailed profiling. The genome-wide expression profile of NIH 3T3 cells was carried out by whole mouse genome microarrays. The mRNA expression levels of most genes tested were significantly changed after 1 h of mechanical stimulation. Subsequently, the mRNA samples of the 1-h stretched cells were hybridized to obtain a gene expression profile using microarrays. Real-time PCR results are shown to agree with the microarray results. The early response genes, such as Egr1, Egr2, Fos, Myc, Rela, Fas, Egfr1, and Fgfr2 playing a role in stretch activation of the signal transduction pathways were significantly up-regulated, whereas the only significantly down-regulated gene is Tfrc. Low level of mechanical stimulation was found to effect the expression of early responsive genes initiates alteration of NIH 3T3 behaviors to control the homeostasis of the fibroblasts.