title: Increased expression of S100 calcium binding protein A8 in GM-CSF-stimulated neutrophils leads to the increased expressions of IL-8 and IL-16.
abstract: OBJECTIVE
  In our previous proteomic surveillance, we found that at least 11 proteins in neutrophils were increased more than 2.5-fold by the stimulation of GM-CSF. In this paper, focusing on one of the 11 proteins, S100 calcium binding protein A8 (S100A8), we tried to elucidate the effect of S100A8 and the cooperative effect of S100A8 and GM-CSF on production and secretion of cytokines of neutrophils.
  
  
  METHODS
  S100A8 in neutrophil was detected by western blotting, and concentrations of S100A8 in synovial fluid (SF) from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) were measured by ELISA. Cytokine levels in the culture medium of neutrophils incubated with and without S100A8 were measured by an antibody array. IL-8 and IL-16 levels in the culture medium of neutrophils stimulated with S100A8, GM-CSF, and the combination of S100A8 and GM-CSF were measured by ELISA. The mRNA levels of IL-8 and IL-16 in the stimulated neutrophils were analysed by real-time PCR.
  
  
  RESULTS
  The western blotting analysis confirmed that S100A8 is up-regulated in neutrophil by the stimulation of GM-CSF. Furthermore, the ELISA analysis confirmed that S100A8 was significantly elevated in SF of patients with RA compared to SF of patients with OA. S100A8 induced mRNA expression and secretion of IL-8 and IL-16. S100A8 further enhanced production of IL-8 by GM-CSF but not that of IL-16.
  
  
  CONCLUSIONS
  These data suggest that S100A8 may be involved in the exacerbation of RA, and that S100A8 may be a therapeutic target of RA.
authors.affiliation: Clinical Proteomics & Molecular Medicine, St. Marianna University Graduate School of Medicine, Kawasaki, Japan. katano.masayoshi@mw.medience.co.jp
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Katano
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okamoto
authors.forename: Naoya
authors.initials: N
authors.lastname: Suematsu
authors.forename: Manae S
authors.initials: MS
authors.lastname: Kurokawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Kayo
authors.initials: K
authors.lastname: Masuko
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yudoh
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D040501:Calgranulin A / Q000008:administration & dosage / Q000378:metabolism*; D002478:Cells, Cultured; D004357:Drug Synergism; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D019410:Interleukin-16 / Q000235:genetics* / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D013582:Synovial Fluid / Q000378:metabolism
chemical_list: C508606:CXCL8 protein, human; D040501:Calgranulin A; D019410:Interleukin-16; D016209:Interleukin-8; D012333:RNA, Messenger; D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor