[Effect of titanium dioxide nanoparticles on protein expression profiles in rat liver microsomes]

There was studied an influence of intragastric administration of titanium dioxide (anatase form) nanoparticles (NP) on protein expression profiles in rat's liver microsomes by methods of proteomics. Animals received water suspension of NP in doses from 0,1 to 10 mg per kg body weight intragastrically daily during 28 days. Microsomes were isolated from liver by means of preparative ultracentrifugation. Proteins composition was studied by 2D-electrophoresis in acrylamide gel. Protein spots were identified by MALDI-TOF analysis. The results demonstrated appearance of 53 new protein spots and disappearance of 19 spots in animals subjected to NP irrespective of their dose. In addition 25 new spots appeared and 3 disappeared in higher doses of NP when compared to low dose group and control animals. Mass-spectrum analysis showed presence of few polypeptides registered in international database among proteins expressed under influence of NP. One of this dominant expressed proteins corresponded to enzyme glutathione transpherase Mu 2 isoform (M=41,55 kD, pI=8,0). The conclusion was made of well advances of proteomic analysis in artificial NP influences on biosynthetic processes estimation.