Effects of different concentrations of tumor necrosis factor-α on A549 cells

Objective To observe the effects of different concentrations of TNF-α on the protection,inflammation and apoptosis of A549 cells.Methods A549 cells were treated with different concentrations of TNF-α(0,1,10,25 and 50 ng/mL) for six hours respectively.The cell viability was observed by MTT assay.Reactive oxygen species(ROS) levels were detected by applying ROS fluorescence probe DCFH-DA.The gene expressions of Nrf-2 and NF-κB were detected by RT-PCR.The cells were treated by nuclear fluorescence staining DAPI,and the apoptosis was observed by fluorescence microscope.Results TNF-α at the concentration of 0,1,10,25 and 50 ng/mL had no effect on A549 cell viability(all P0.05),and compared with the control group,the cell viability was decreased at the concentration of 100 ng/mL(P0.05).With the increase of TNF-α concentration,the generation of ROS increased(all P0.05),the mRNA expression of Nrf-2 decreased(all P0.05),the mRNA expression of NF-κB increased(all P0.05),and the apoptosis rate was on the rise.Conclusions Different concentrations of TNF-α can make A549 cells to produce different amounts of ROS and cellular effects.With the increase of TNF-α concentration,the cell damage is aggravated.Its mechanism may be related to the increasing amount of ROS induced by the increasing TNF-α concentration.