title: Inhibition of inflammatory mediators and related signaling pathways by macrophage-stimulating protein in rheumatoid arthritis synovial fibroblasts.
abstract: OBJECTIVE
  To evaluate the mechanism of macrophage-stimulating protein (MSP)-mediated inhibition of inflammatory cytokine and chemokine production in rheumatoid arthritis synovial fibroblasts (RASF).
  
  
  METHODS
  RASF were treated with different concentrations (0, 0.5, 1, 5 and 10 ng/ml) of MSP with or without 1 μg/mL lipopolysaccharide (LPS). The protein expressions of IL-1β, TNF-α, IL-18, MIP-1, MCP-1, RANTES and PGE(2) were analyzed by enzyme-linked immunosorbent assays (ELISA). The total nitric oxide (NO) concentration was determined using the Griess reaction. The protein expressions of iNOS, COX-2, NF-κB(p-p65), IKB-α, IKB-β, p-P38, p-Erk1/2 (P-P42/44) and p-AKT were detected by Western blotting.
  
  
  RESULTS
  MSP markedly inhibited expression of inflammatory cytokines (IL-1β, TNF-α and IL-18), chemokines (MIP-1, MCP-1 and RANTES) and iNOS, NO, COX-2 and PGE(2) in RASF stimulated by LPS. MSP treatment decreased expressions of p-IκBα, p-IKBβ and p-P65 in RASF in a concentration-dependent manner. Expressions of p-AKT, p-p38 and p-Erk1/2 were also inhibited markedly in RASF stimulated by LPS after treatment with MSP in a concentration-dependent manner.
  
  
  CONCLUSIONS
  MSP could inhibit the inflammatory cycle by suppressing inflammatory mediators and activation of NF-κB as well. The inhibitory effect of MSP on LPS-stimulated RASF may act through suppression of multiple signals such as the PI3K/AKT and/or MAPK pathways.
authors.affiliation: Department of Hematology, The First Affiliated Hospital, School of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou, 310003, People's Republic of China. tongxiangmin@163.com
authors.forename: Xiang-Min
authors.initials: XM
authors.lastname: Tong
authors.forename: Jian-Chao
authors.initials: JC
authors.lastname: Wang
authors.forename: Yuedi
authors.initials: Y
authors.lastname: Shen
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Xie
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Jin
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000473:pathology; D002478:Cells, Cultured; D018925:Chemokines / Q000276:immunology; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016207:Cytokines / Q000276:immunology; D015232:Dinoprostone / Q000276:immunology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000502:physiology; D017228:Hepatocyte Growth Factor / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors*; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000276:immunology / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000276:immunology; D013583:Synovial Membrane / Q000166:cytology*; D051996:Transcription Factor RelA / Q000378:metabolism
chemical_list: D018925:Chemokines; D016207:Cytokines; C083487:I kappa B beta protein; D020672:I-kappa B Proteins; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; C000606204:NFKBIA protein, human; D011518:Proto-Oncogene Proteins; D051996:Transcription Factor RelA; C082332:macrophage stimulating protein; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide; D017228:Hepatocyte Growth Factor; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D015232:Dinoprostone