title: Histone deacetylase inhibitors suppress mechanical stress-induced expression of RUNX-2 and ADAMTS-5 through the inhibition of the MAPK signaling pathway in cultured human chondrocytes.
abstract: OBJECTIVE
  To investigate the inhibitory effects and the regulatory mechanisms of histone deacetylase (HDAC) inhibitors on mechanical stress-induced gene expression of runt-related transcription factor (RUNX)-2 and adisintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-5 in human chondrocytes.
  
  
  METHODS
  Human chondrocytes were seeded in stretch chambers at a concentration of 5 × 10(4)cells/chamber. Cells were pre-incubated with or without HDAC inhibitors (MS-275 or trichostatin A; TSA) for 12h, followed by uniaxial cyclic tensile strain (CTS) (0.5Hz, 10% elongation), which was applied for 30 min using the ST-140-10 system (STREX, Osaka, Japan). Total RNA was extracted and the expression of RUNX-2, ADAMTS-5, matrix metalloproteinase (MMP)-3, and MMP-13 at the mRNA and protein levels were examined by real-time polymerase chain reaction (PCR) and immunocytochemistry, respectively. The activation of diverse mitogen-activated protein kinase (MAPK) pathways with or without HDAC inhibitors during CTS was examined by western blotting.
  
  
  RESULTS
  HDAC inhibitors (TSA: 10 nM, MS-275: 100 nM) suppressed CTS-induced expression of RUNX-2, ADAMTS-5, and MMP-3 at both the mRNA and protein levels within 1h. CTS-induced activation of p38 MAPK (p38), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) MAPKs was downregulated by both HDAC inhibitors.
  
  
  CONCLUSIONS
  The CTS-induced expression of RUNX-2 and ADAMTS-5 was suppressed by HDAC inhibitors via the inhibition of the MAPK pathway activation in human chondrocytes. The results of the current study suggested a novel therapeutic role for HDAC inhibitors against degenerative joint disease such as osteoarthritis.
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Density and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama City, Okayama 700-8558, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: K
authors.initials: K
authors.lastname: Nishida
authors.forename: T
authors.initials: T
authors.lastname: Furumatsu
authors.forename: A
authors.initials: A
authors.lastname: Yoshida
authors.forename: M
authors.initials: M
authors.lastname: Ozawa
authors.forename: T
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000071116:ADAMTS5 Protein; D015153:Blotting, Western; D019902:Chondrocytes / Q000378:metabolism*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors*; D060888:Real-Time Polymerase Chain Reaction; D013314:Stress, Mechanical; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D056572:Histone Deacetylase Inhibitors; C493709:RUNX2 protein, human; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; D053509:Matrix Metalloproteinase 13; D019278:Matrix Metalloproteinase 3