title: Regulation of mechanical stress-induced MMP-13 and ADAMTS-5 expression by RUNX-2 transcriptional factor in SW1353 chondrocyte-like cells.
abstract: OBJECTIVE
  To investigate the mechanism of mechanical stress-induced expression and regulation of aggrecanases and examine the role of runt-related transcription factor 2 (RUNX-2) in chondrocyte-like cells.
  
  
  METHODS
  SW1353 cells were seeded onto stretch chambers at a concentration of 5×10⁴ cells/chamber, and a uni-axial cyclic tensile strain (CTS) (0.5 Hz, 10% stretch) was applied for 30 min. Total RNA was extracted, reverse transcribed, and analyzed by polymerase chain reaction (PCR) and real-time PCR. RUNX-2 overexpression and small interfering RNA (siRNA) targeting RUNX-2 were used to investigate the role of RUNX-2 in CTS-induced gene expression. The involvement of diverse mitogen-activated protein kinase (MAPK) pathways in the activation of RUNX-2, MMP-13 and ADAMTS-5 during CTS was examined by Western blotting.
  
  
  RESULTS
  CTS induced expression of RUNX-2, MMP-13, ADAMTS-4, -5, and -9. Overexpression of RUNX-2 up-regulated expression of MMP-13 and ADAMTS-5, whereas RUNX-2 siRNA resulted in significant down-regulation of mechanically-induced MMP-13 and ADAMTS-5 expression. CTS induced activation of p38 MAPK, and CTS induction of RUNX-2, MMP-13 and ADAMTS-5 mRNA was down-regulated by the selective p38 MAPK inhibitor SB203580 but not by the p44/42 MAPK inhibitor U0126, or the JNK MAPK inhibitor JNK inhibitor II.
  
  
  CONCLUSIONS
  RUNX-2 might have a role as a key downstream mediator of p38's ability to regulate mechanical stress-induced MMP-13 and ADAMTS-5 expression.
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: T
authors.initials: T
authors.lastname: Tetsunaga
authors.forename: K
authors.initials: K
authors.lastname: Nishida
authors.forename: T
authors.initials: T
authors.lastname: Furumatsu
authors.forename: K
authors.initials: K
authors.lastname: Naruse
authors.forename: S
authors.initials: S
authors.lastname: Hirohata
authors.forename: A
authors.initials: A
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism*; D000071116:ADAMTS5 Protein; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000502:physiology*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D013314:Stress, Mechanical; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D004791:Enzyme Inhibitors; C493709:RUNX2 protein, human; D048051:p38 Mitogen-Activated Protein Kinases; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; D053509:Matrix Metalloproteinase 13