Figure 3.

ELF-PEMF exposure induces gene expression of intracellular antioxidative enzymes in hOBs. (a) Basal expression levels of oxidative stress (•O₂ ⁻ and H₂O₂) related genes in hOBs was determined using the RT² Profiler PCR Array human oxidative stress plus (Qiagen, Hilden, Germany). (b–e) Semi-quantitative RT-PCR revealed that expression of SOD2, CAT, GPX3 and GSR was increased by repetitive exposures to ELF-PEMF (7 min per day) during the osteogenic differentiation of hOBs. Densitometric analysis (ImageJ software) was performed with individual samples (N = 12) analyzed twice (n = 2) to reduce small loading differences. The mean signal intensity of cells on day 0 was set as reference. *p < 0.05, **p < 0.01 and ***p < 0.001 as indicated (Kruskal-Wallis test followed by Dunn’s multiple comparison test, α = 0.05).