Differential expression of WNTs and FRPs in the synovium of rheumatoid arthritis and osteoarthritis

Biochem Biophys Res Commun. 2006 Jul 14;345(4):1615-20. doi: 10.1016/j.bbrc.2006.05.075. Epub 2006 May 22.

Abstract

Synovial cells of the joint play a key role in the progression of rheumatoid arthritis (RA). However, the mechanism(s) that triggers aggression of RA synovial cells but not other arthropathies such as osteoarthritis (OA) is not clear. Here we examined expression of WNT and the WNT inhibitor, secreted frizzled-related protein (FRP), in RA and OA synovium by reverse transcription-PCR. WNT10B was most frequently detected in RA synovium, and FRP1, FRP2, and FRP4 in OA synovium. Immunohistochemistry localized WNT10B and FRP1 in synovial lining cells, fibroblasts, and endothelial cells in RA and OA synovium, respectively, and WNT10B expression was increased in parallel with the degree of inflammatory cell infiltration and tissue fibrosis. Membrane-type 1 matrix metalloproteinse (MT1MMP) was upregulated by WNT10B and activation of WNT signaling. MT1MMP immunolocalized to cells identical to WNT10B and beta-catenin staining. The present study demonstrated that WNTs and FRPs are differentially expressed in RA and OA synovium, and suggests an involvement in the pathology of these diseases.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthritis, Rheumatoid / genetics*
  • Arthritis, Rheumatoid / metabolism
  • Blotting, Western
  • Gene Expression Profiling*
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Matrix Metalloproteinases / genetics
  • Matrix Metalloproteinases / metabolism
  • Matrix Metalloproteinases, Membrane-Associated
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Osteoarthritis / genetics*
  • Osteoarthritis / metabolism
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Synovial Membrane / metabolism*
  • Synovial Membrane / pathology
  • Wnt Proteins / genetics*
  • Wnt Proteins / metabolism
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Intercellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Proto-Oncogene Proteins
  • SFRP1 protein, human
  • SFRP2 protein, human
  • WNT10B protein, human
  • Wnt Proteins
  • beta Catenin
  • Matrix Metalloproteinases
  • Matrix Metalloproteinases, Membrane-Associated