Expression data after irradiating mMSCs for 2 hours with single frequency terahertz laser source

We report that terahertz (THz) irradiation of mouse mesenchymal stem cells with a pulsed broadband (centered at 10 THz) source, or a single-frequency, 2.52 THz, (SF) laser source, both with weak average power (<1mW/cm2), results in specific heterogenic changes in gene expression. The insignificant differential expression of heat shock and stress related genes as well as our temperature measurements imply a non-thermal response. The microarray survey and RT-PCR experiments demonstrate that at different irradiation conditions distinct groups of genes are activated. Stem cells irradiated for 12 hours with the broadband THz source exhibit an accelerated differentiation toward adipose phenotype, while the 2-hour (broadband or SF) irradiation affects genes transcriptionally active in pluripotent stem cells. Phenotypic and gene expression differences suggest that the THz effect depends on irradiation parameters such as duration and type of THz source, and on the level of stem cell differentiation. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. We propose that THz radiation has potential for non-contact control of cellular gene expression. Growing in petri dish mouse mesenchymal stem cell cultures are irradiated for 2 hours with a single-frequency (2.52 THz) CW laser source. Three independent biological experiments were conducted. In each experiment, a control mMSC culture was placed adjacent to the irradiated sample, and the temperature was kept at 26-27ºC for both the control and the irradiated sample. Immediately after completing the irradiation, total RNA was extracted from the irradiated sample and the control, and microarrays were used to identify differential changes in gene expression between the irradiated sample and its respective control. In each experiment, the mMSC cultures were synchronized to be at the same differentiation time point immediately before the irradiation.