Molecular Mechanisms of 2, 3′, 4, 4′, 5-Pentachlorobiphenyl-Induced Thyroid Dysfunction in FRTL-5 Cells
Fig 5
FoxO3a plays a role in the down-regulation of NIS expression in PCB118-treated FRTL-5 cells.
FoxO3a was knocked down by FoxO3a-siRNA in FRTL-5 cells, and the cells were treated with PCB118 at 25 nM. Whole cell lysates were analyzed by western blotting using antibodies recognizing FoxO3a, p-FoxO3a, and NIS (A and B). FoxO3a over-expression was induced by the pcDNA3-FoxO3a plasmid, and the cells were harvested for the measurement of NIS promoter activity (C). Results show sections of blots from one experiment of the three that yielded similar results (A) or represent the mean ± SD of three independent experiments (B and C). GAPDH served as the loading control in western blotting.*p < 0.05, compared with the DMSO control group transfected with siRNA or the pcDNA3-FoxO3a plasmid; #p < 0.05, compared with the 25 nM PCB118-treated group transfected with the NC or pcDNA3 plasmid; ##p < 0.05, compared with the DMSO control group transfected with the NC or pcDNA3 plasmid. The relative ratio of target protein/GAPDH and promoter activity in solvent control group was set as 1.