title: Investigation of proteome changes in osteoclastogenesis in low serum culture system using quantitative proteomics.
abstract: BACKGROUND
  RAW 264.7 cells can differentiate into osteoclasts when cultured in medium supplemented with 1 % FBS. However, the proteomic changes in the development of RAW 264.7 cells into osteoclasts in low serum culture system have not been elucidated. Therefore, we conducted quantitative proteomics analysis to investigate proteomic changes during osteoclastogenesis in low serum culture system.
  
  
  RESULTS
  Our study confirmed that mature multinucleated osteoclasts were generated in a low serum culture system, validated by upregulated expression of 15 characteristic marker proteins, including TRAP, CTSK, MMP9, V-ATPase and ITGAV. Proteomics results demonstrated that 549 proteins expressed differentially in osteoclastogenesis in low serum culture system. In-depth bioinformatics analysis suggested that the differentially expressed proteins were mainly involved in mitochondrial activities and energy metabolism, including the electron transport chain pathway, TCA cycle pathway, mitochondrial LC-fatty acid beta-oxidation pathway and fatty acid biosynthesis pathway. The data have been deposited to the ProteomeXchange with identifier PXD001935.
  
  
  CONCLUSIONS
  Osteoclast formation is an ATP consuming procedure, whether occurring in a low serum culture system or a conventional culture system. In contrast to osteoclasts formed in conventional culture system, the fatty acid biosynthesis pathway was upregulated in osteoclasts cultured in low serum condition.
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, Fuxing Road 28#, Haidian District, Beijing, 100853 China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xiong
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, Fuxing Road 28#, Haidian District, Beijing, 100853 China.
authors.forename: Lihai
authors.initials: L
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, DongdanSantiao 5#, Dongcheng District, Beijing, 100005 China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Zhan
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, DongdanSantiao 5#, Dongcheng District, Beijing, 100005 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ge
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, Fuxing Road 28#, Haidian District, Beijing, 100853 China.
authors.forename: Peifu
authors.initials: P
authors.lastname: Tang
keywords: Bioinformatics; Cell culture; Osteoclast; Proteomics