Proteome analysis in the process of inducing C2C12 cells differentiation towards osteoblast by BMP-2 based on iTRAQ technology

Objective To apply iTRAQ technology to observe changes in protein expression group in the process of inducing C2C12 cells differentiation towards osteoblast by BMP-2. Methods The myoblast C2C12 cells were seeded in BMP-2 induced differentiation system for differentiation induction. In the 7th day, differentiation protein was extracted and labeled with iTRAQ reagent. Then, mass spectrometric detection, data analysis of differentially expressed proteins, and analysis of biological information were carried out. Results 23 significantly differentially expressed protein spots were screened by BMP-2-induced myoblast C2C12 differentiated cell protein expression profile analysis, where the protein was labeled with iTRAQ reagent. 8 protein points were up-regulated, and 15 protein points were down-regulated. Trend classification found that the above differential protein had differential expression in each period of C2C12 cell osteogenic differentiation (1-7 days). Part of up-regulated protein in the early differentiation period showed high expression level; part of upregulated protein in the late differentiation period showed high expression level; similarly, part of down-regulated protein in the early differentiation period presented low expression level; part of downregulated protein in the late differentiation period showed low expression level. Preliminary identification showed SERCA3, Cytochrome b5, S100A4, ATPase inhibitor and ATPIF1 presented dynamic changes, which suggests that these proteins may be related to inducing osteogenic differentiation mechanism. Conclusion The results of differential protein expression trend show the necessity of full monitoring of C2C12 cells osteogenic differentiation and indicate that iTRAQ technology is an effective method of studying protein changes of cellular molecule. Five proteins including SERCA3, Cytochrome b5, S100A4, ATPase inhibitor and ATPIF1 can be used as candidate targets for osteogenic differentiation mechanism research. Key words: Bone morphogenetic protein 2; Osteoblasts; Cell differentiation; Proteomics