Two types of MWNTs with different surface modifications induce differential expression of proteins in RAW264.7 cells

Objective:To compare the different expression of protein in RAW264.7 macrophage cells induced by two types of MWNTs(multi-walled carbon nanotubes)with different surface modifications(acid-treated MWNTs and tau-MWNTs modified by taurine).Methods:Treating cells with both types of MWNTs in 20 mg/L and 24 h,with a blank-control group set.Cells are lysed by using urea and by ultrasonicating in ice bath,then total proteins of cells are extracted.Using two-dimensional gel electrophoresis to separate total proteins of cells,searching for the differential expressed protein spots on the images of the gels with silver staining.Identifying the differentially expressed proteins via mass spectrometry,and studying the mechanism of effects on cells imposed by two types of MWNTs at protein level.Results:There are 13 spots of protein with notably differential expression among three treated groups(including blank controls).Their functions involve apoptosis-related,calcium-binding,cell-cycle related,DNA synthesis,folding of proteins,and energy metabolism,etc.The results are consistent with our previous studies about the cytotoxicity of Both types of MWNTs including induction of apoptosis and mitochodira damage.Conclusion:Both two types of MWNTs could induce alteration of protein expression in RAW264.7 cells.With different surface modifications,they imposed different effects.High throughout proteomics could be applied in toxicity assessment and mechanism investigation about carbon nanotubes.