title: Matrix metalloproteinase-3 on ligamentum flavum in degenerative lumbar spondylolisthesis.
abstract: METHODS
  Human ligamentum flavum (LF) was examined for the activity level of matrix metalloproteinase-3 (MMP-3) in degenerative spondylolithesis (DS) patients using immunohistochemistry, Western blot, reverse transcriptase-polymerase chain reaction (RT-PCR), and quantitative real-time PCR.
  
  
  OBJECTIVE
  To investigate the hypothesis that the activity of MMP-3 is elevated in LF of DS patients, which might contribute to DS pathogenesis.
  
  
  BACKGROUND
  MMP-3 is a proteinase produced by connective tissue cells and is responsible for the degradation and modification of extracellular matrix molecules. MMP-3 activity has been established in articular cartilage, synovial membrane, and intervertebral discs, but not in the LF.
  
  
  METHODS
  The experimental group consisted of 18 patients with DS and the control group consisted of 18 patients with spinal stenosis (SS) without any instabilities. MMP-3 expression was measured with in situ using immunohistochemistry and both for mRNA and protein levels.
  
  
  RESULTS
  The MMP-3 positive cell ratio in the LF observed in DS patients was substantially higher than in SS patients (P = 0.030). In Western blot, the average optical density (OD) of MMP-3 was higher in LF of DS than of SS (P = 0.028). There was greater MMP-3 expression in DS patients as quantified by RT-PCR (P = 0.004).
  
  
  CONCLUSIONS
  Our study shows that MMP-3 expression in the LF of DS patients was significantly higher than in SS patients. Increased MMP-3 expression may be associated with the degenerative changes of LF in DS patients comprising one of the mechanisms of pathogenesis in DS.
authors.affiliation: Department of Orthopaedic Surgery, Kang-Nam St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Oh
authors.forename: Kee-Yong
authors.initials: KY
authors.lastname: Ha
mesh_terms: D000368:Aged; D015153:Blotting, Western; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017843:Ligamentum Flavum / Q000201:enzymology* / Q000378:metabolism; D008159:Lumbar Vertebrae / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013130:Spinal Stenosis / Q000201:enzymology* / Q000235:genetics; D013168:Spondylolisthesis / Q000201:enzymology* / Q000235:genetics
chemical_list: D019278:Matrix Metalloproteinase 3