title: Matrix metalloproteinase 13 in the ligamentum flavum from lumbar spinal canal stenosis patients with and without diabetes mellitus.
abstract: BACKGROUND
  Lumbar spinal canal stenosis (LSCS) is one of the most common spinal disorders in the elderly, and ligamentum flavum (LF) hypertrophy is an important cause of LSCS. Matrix metalloproteinase 13 (MMP13) can degrade fibrillar collagens and elastic microfibrils, and is involved in inflammation and fibrosis. The purpose of this study was to compare the expression of MMP13 in the LF from LSCS patients with diabetes mellitus [DM (+)] with that in the LF from patients without DM [DM (-)] and to analyze the relationship among DM, MMP13 expression, and LF hypertrophy.
  
  
  METHODS
  LFs from 11 DM (+) and 24 DM (-) LSCS patients were analyzed in this study. Histology analysis using hematoxylin and eosin and Masson's trichrome stain was performed for each LF. The expression of MMP13 was analyzed by quantitative real-time PCR. The thickness of LF was measured by CT.
  
  
  RESULTS
  In the LF from DM (+) LSCS patients, the elastic fibers were more disorganized and had lower volumes than in the LF from DM (-) LSCS patients, while more fibrotic tissue was observed in the LF from DM (+) than from DM (-) LSCS patients. MMP13 expression was significantly higher in the LF from DM (+) LSCS patients (0.46 ± 0.61 vs. 0.05 ± 0.09, P = 0.002). The LF from the DM (+) LSCS patients was significantly thicker than that from the DM (-) LSCS patients (5.0 ± 0.9 vs. 3.1 ± 0.8 mm, P < 0.01), and the thickness was correlated with the expression of MMP13 (correlation coefficient = 0.43, P = 0.01, Pearson's correlation test).
  
  
  CONCLUSIONS
  DM-related MMP13 expression can be one of the factors contributing to fibrosis and hypertrophy of the LF. Further research on the mechanism of this process may lead to new therapies for LF hypertrophy.
authors.affiliation: Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan.
authors.forename: Guanyu
authors.initials: G
authors.lastname: Cui
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Miyauchi
authors.forename: Naobumi
authors.initials: N
authors.lastname: Hosogane
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuji
authors.forename: Ken
authors.initials: K
authors.lastname: Ishii
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakamura
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Chiba
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D048909:Diabetes Complications / Q000378:metabolism*; D005260:Female; D006801:Humans; D017843:Ligamentum Flavum / Q000378:metabolism*; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000096:biosynthesis*; D008875:Middle Aged; D013130:Spinal Stenosis / Q000150:complications / Q000378:metabolism*
chemical_list: D053509:Matrix Metalloproteinase 13