title: Neuropeptide FF attenuates RANKL-induced differentiation of macrophage-like cells into osteoclast-like cells.
abstract: OBJECTIVE
  Neuropeptide FF (NPFF) has been implicated in many physiological processes but not osteoclastogenesis. We previously demonstrated that NPFF modulates the viability and nitric oxide (NO) production of RAW264.7 macrophages. This study was designed to investigate the effect of NPFF on receptor activator of nuclear factor κB ligand (RANKL)-mediated differentiation of RAW264.7 cells into osteoclast-like cells.
  
  
  METHODS
  RAW264.7 cells were cultured in 96-stripwell plates or in Corning Osteo Assay Surface 96-well plates in the presence of various concentrations of NPFF with or without RANKL for 3 or 6 d. The differentiation of osteoclast-like cells was analyzed by tartrate-resistant acid phosphatase (TRAP) stain, TRAP activity and bone resorption capacity, respectively. The mRNA expression of NPFF2 receptor (NPFFR2) and osteoclast genes was evaluated by using real-time quantitative PCR which includes TRAP, RANK (receptor activator of NF-κB), Cathepsin K, MMP-9 (matrix metallopeptidase 9), Intβ3 (integrin β3) and NFATc1 (nuclear factor of activated T cells cytoplasmic 1). In addition, the influence of NPFF on the cell viability and NO release of RAW264.7 cells was measured by MTT assay and Griess method, respectively.
  
  
  RESULTS
  NPFF dose-dependently inhibited RANKL-induced osteoclast-like cells differentiation including TRAP-positive cell formation, TRAP activity and bone resorption capacity. Moreover, NO release and osteoclast gene expression of osteoclast-like cells were downregulated by NPFF. In addition, NPFFR2 gene expression in osteoclast-like cells was augmented in response to NPFF treatment.
  
  
  CONCLUSIONS
  Our findings showed that NPFF could attenuate osteoclast-like cells differentiation in an in vitro osteoclastogenesis model.
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Dijie
authors.initials: D
authors.lastname: Li
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Shang
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China. Electronic address: qianair@nwpu.edu.cn.
authors.forename: Airong
authors.initials: A
authors.lastname: Qian
mesh_terms: D000135:Acid Phosphatase; D001862:Bone Resorption; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D015536:Down-Regulation; D007527:Isoenzymes; D008264:Macrophages / Q000187:drug effects*; D009842:Oligopeptides / Q000494:pharmacology*; D010010:Osteoclasts / Q000187:drug effects*; D053245:RANK Ligand / Q000037:antagonists & inhibitors*; D060888:Real-Time Polymerase Chain Reaction; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D007527:Isoenzymes; D009842:Oligopeptides; D053245:RANK Ligand; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase
keywords: Bone resorption; Differentiation; Neuropeptide FF; Npff receptor 2; Osteoclast-like cells