title: Disorders in angiogenesis and redox pathways are main factors contributing to the progression of rheumatoid arthritis: a comparative proteomics study.
abstract: OBJECTIVE
  To clarify the pathogenesis of rheumatoid arthritis (RA) by comparing protein expression in fibroblast-like synoviocytes (FLS) from patients with RA with that in FLS from normal subjects, using proteomics analysis.
  
  
  METHODS
  Proteins extracted from primary cultures of FLS obtained from 50 patients with RA and 10 normal subjects were analyzed by automated 2-dimensional nano-electrospray ionization liquid chromatography tandem mass spectometry. Differentially expressed proteins were screened by 2-sample t-test (P < 0.05) and fold change (>1.5), based on the bioinformatics analysis. The expression of vasculature development-related proteins (Thy-1, connective tissue growth factor [CTGF], and thrombospondin 1 [TSP-1]) and redox-related proteins (superoxide dismutase 2 [SOD2]) in synovial tissue was confirmed by real-time polymerase chain reaction and Western blotting. The effect of Thy-1 and CTGF knockdown on Thy-1, CTGF, TSP-1, and vascular endothelial growth factor (VEGF) was analyzed by RNA interference experiments.
  
  
  RESULTS
  According to the criteria of having >1 unique peptide per protein present and a false discovery rate of ≤5%, 1,060 proteins were identified from patients with RA, and 1,292 proteins were identified from normal subjects, from which 100 differentially expressed proteins were screened out from the RA proteins. Of these, 46 proteins were up-regulated, and the remaining 54 proteins were down-regulated. Gene ontology and pathway analyses showed that 6 vasculature development-related proteins were up-regulated, including Thy-1, CTGF, and TSP-1, while 11 redox-related proteins were down-regulated, including SOD2. The results were consistent with those obtained using mass spectrometry. Thy-1, VEGF, CTGF, and TSP-1 were down-regulated after Thy-1 knockdown, and VEGF and CTGF were down-regulated after CTGF knockdown. Recombinant human CTGF could enhance proliferation and Transwell migration of human umbilical vein endothelial cells.
  
  
  CONCLUSIONS
  Up-regulation of vasculature development-related proteins and down-regulation of redox-related proteins in FLS are predominant factors that may contribute to the pathogenesis of RA.
authors: Second Military Medical University, Shanghai, China.
authors: Jian-Guang
authors: JG
authors: Wang
authors: Wei-Dong
authors: WD
authors: Xu
authors: Wei-Tao
authors: WT
authors: Zhai
authors: Yan
authors: Y
authors: Li
authors: Jie-Wei
authors: JW
authors: Hu
authors: Bo
authors: B
authors: Hu
authors: Ming
authors: M
authors: Li
authors: Ling
authors: L
authors: Zhang
authors: Wei
authors: W
authors: Guo
authors: Jian-Peng
authors: JP
authors: Zhang
authors: Liang-Hua
authors: LH
authors: Wang
authors: Bing-Hua
authors: BH
authors: Jiao
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D055513:Connective Tissue Growth Factor / Q000235:genetics / Q000378:metabolism; D018450:Disease Progression; D006801:Humans; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology; D019700:Thrombospondin 1 / Q000235:genetics / Q000378:metabolism; D018800:Thy-1 Antigens / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D000099156:Superoxide Dismutase 2
chemical_list: D055513:Connective Tissue Growth Factor; D013482:Superoxide Dismutase; D019700:Thrombospondin 1; D018800:Thy-1 Antigens; D042461:Vascular Endothelial Growth Factor A; D000099156:Superoxide Dismutase 2; C526317:CCN2 protein, human