title: Proteomic study of different culture medium serum volume fractions on RANKL-dependent RAW264.7 cells differentiating into osteoclasts.
abstract: BACKGROUND
  Cultivation of osteoclasts is a basic tool for investigating osteolytic bone diseases. Fetal bovine serum (FBS) is the standard supplement used for in vitro cell culture medium. Typically, the serum volume fraction used for osteoclast cultivation is 10%. In this study, we investigated the use of a low serum (1% FBS) model for culturing osteoclasts.
  
  
  RESULTS
  To confirm the validity of this model for use in osteoclast research, we compared the capacity for osteoclastogenesis and bone resorption of RANKL-induced RAW 264.7 cells cultured in medium supplemented with 10% FBS and 1% FBS. Osteoclasts were successfully generated in medium supplemented with 1% FBS, and exhibited prolonged longevity and similar bone resorbing ability to those generated in medium supplemented with 10% FBS, although the osteoclasts were smaller in size. Proteomics and bioinformatics analyses were performed to assess the suitability of osteoclasts formed in low serum-containing medium for use in research focusing on osteoclast differentiation and function. Our study demonstrated that a total of 100 proteins were differentially expressed in cells cultured in medium containing 1% FBS, of which 29 proteins were upregulated, and 71 proteins were downregulated. Bioinformatics analysis showed that the electron transport chain and oxidative phosphorylation pathways were downregulated obviously; however, the osteoclast signaling pathway was unaffected. The data have been deposited to the ProteomeXchange with identifier PXD001935.
  
  
  CONCLUSIONS
  Our study provides clear evidence of the validity of the low serum model for use in studying RANKL-dependent osteoclasts differentiation and bone resorption with the advantage of prolonged survival time.
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: Department of Obstetrics and Gynecology, The Second Artillery General Hospital of Chinese PLA, Xinjiekouwai Street 16# Xicheng district, Beijing, 100088 China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Xin
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: Yanpan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, Fuxing Road 28# Haidian district, Beijing, 100853 China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Peng
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
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
keywords: Bioinformatics; Cell Culture; Osteoclast; Proteomics