Induction of p65 nuclear translocation and NF-κB activation by metallic nickel particles.

<p>JB6 cells, stably transfected with NF-κB luciferase reporter plasmid, were seeded onto 24-well plate and incubated overnight. Cells were treated with/without metallic nickel nano- or fine particles for 24 h. (A) Effect of nickel particles on nuclear translocation of the p65 subunit of NF-κB as measured by indirect immunofluorescence analysis using an anti-p65 primary antibody. The bright greenish areas represent nuclei that stained with anti-p65 antibody. After treatments, cells were fixed, permeabilized, blocked, and stained with NF-κB monoclonal p65 antibody for 3 h. Alexa Fluor 488 goat anti-rabbit secondary antibody was added for 1 h. NF-κB is 100% expression in all cell cytoplasm, metallic nickel nano- or fine particles may induce NF-κB translocation from cytoplasm into the cell nucleus. (B) The NF-κB activity was measured by the luciferase activity assay. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092418#s3" target="_blank">Results</a> are mean and standard error of four assay wells. The experiment was repeated two times. * <i>P</i><0.05 versus control; † <i>P</i><0.05 versus fine particles. TPA (20 ng/ml) was set as a positive control.