title: Hyaluronan suppresses mechanical stress-induced expression of catabolic enzymes by human chondrocytes via inhibition of IL-1β production and subsequent NF-κB activation.
abstract: OBJECTIVE
  To investigate the inhibitory effect of hyaluronan (HA) on mechanical stress- induced expression of a disintegrin and metalloproteinase with thrombospondin type 1 motifs (ADAMTS)-4, -5 and matrix metalloproteinase (MMP)-13 by human chondrocytes.
  
  
  METHODS
  Normal human articular chondrocytes were pre-incubated with or without 1.0 mg/mL HA (2700 kDa) for 12 h at 37 °C in stretch chambers, then they were exposed to uni-axial cyclic tensile strain (CTS, 0.5 Hz, 10% elongation). The expression of ADAMTS-4, -5, and MMP-13 were analyzed by real-time polymerase chain reaction and Immunocytochemistry. The concentration of IL-1β in the supernatant was measured using enzyme-linked immunosorbent assay (ELISA). The nuclear translocation of runt-related transcription factor 2 (RUNX-2) and nuclear factor-κB (NF-κB) was examined by ELISA and immunocytochemistry, and phosphorylation of NF-κB was examined by western blotting.
  
  
  RESULTS
  HA inhibited mRNA expression of ADAMTS-4, -5, and MMP13 after 24 h CTS via inhibition of IL-1β secretion and NF-κB activation. However, HA failed to inhibit CTS-induced RUNX-2 expression and subsequent expression of ADAMTS-5 and MMP-13 1 h after CTS.
  
  
  CONCLUSIONS
  Our results demonstrated that HA significantly suppressed mechanical stress-induced expression of catabolic proteases by inhibition of the NF-κB-IL-1β pathway, but did not suppress mechanical stress-induced RUNX-2 signaling.
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama City, Okayama, 700-8558, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Nishida
authors.forename: Aki
authors.initials: A
authors.lastname: Yoshida
authors.forename: Taichi
authors.initials: T
authors.lastname: Saito
authors.forename: Ryozo
authors.initials: R
authors.lastname: Harada
authors.forename: Takahiro
authors.initials: T
authors.lastname: Machida
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000071121:ADAMTS4 Protein; D000071116:ADAMTS5 Protein; D000293:Adolescent; D000328:Adult; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D019483:Disintegrins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000494:pharmacology*; D066298:In Vitro Techniques; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors / Q000378:metabolism; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011348:Procollagen N-Endopeptidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013314:Stress, Mechanical
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D019483:Disintegrins; D053583:Interleukin-1beta; D016328:NF-kappa B; D012333:RNA, Messenger; C493709:RUNX2 protein, human; D006820:Hyaluronic Acid; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; D053509:Matrix Metalloproteinase 13; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human