Expression and regulation of Toll-like receptor 2 by IL-1β and fibronectin fragments in human articular chondrocytes

S. L. Su, C. D. Tsai, C. H. Lee, D. M. Salter, Herng Sheng Lee

Research output: Contribution to journalArticlepeer-review

93 Citations (Scopus)


Objective: The objective of this study was to examine expression and regulation of Toll-like receptor 2 (TLR2) in human articular chondrocytes. Methods: Human articular chondrocytes were enzymatically isolated from normal and osteoarthritic knee cartilage. Immunohistochemistry, Western blotting, and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to assess the expression of toll-like receptors. Following stimulation of chondrocytes in vitro by IL-1β and fibronectin proteolytic fragments, the relative levels of mRNA for TLR2 were determined by quantitative real-time PCR. MyD88 activation and nuclear factor-κB (NF-κB) translocation were evaluated by immunoprecipitation and electrophoretic mobility shift assay, respectively. Results: Human articular chondrocytes mainly expressed TL R1, 2, 5 by RT-PCR. Protein expression of TLR2 was also identified in adult human articular cartilage. TLR2 was upregulated following IL-1β and fibronectin proteolytic fragments stimulation in primary cultures of osteoarthritic articular chondrocytes. Fibronectin proteolytic fragments-induced TLR2 upregulation involved an IL-1β autocrine/ paracrine pathway. Conclusions: TLR2 is expressed in human articular cartilage and is upregulated by proarthritic agents including IL-1β and fibronectin fragments. Signaling through TLR is a novel pro-inflammatory mechanism in osteoarthritis and targeting of these signaling pathways may be of value in treatment of degenerative joint disease.

Original languageEnglish
Pages (from-to)879-886
Number of pages8
JournalOsteoarthritis and Cartilage
Issue number10
Publication statusPublished - Oct 2005
Externally publishedYes


  • Chondrocyte
  • Fibronectin
  • IL-1β
  • Osteoarthritis
  • Toll-like receptor

ASJC Scopus subject areas

  • Biomedical Engineering
  • Rheumatology
  • Orthopedics and Sports Medicine


Dive into the research topics of 'Expression and regulation of Toll-like receptor 2 by IL-1β and fibronectin fragments in human articular chondrocytes'. Together they form a unique fingerprint.

Cite this