Levels of matrix metalloproteinase-9 and its inhibitor in bronchoalveolar lavage cells of asthmatic children

Fetal Pediatr Pathol. 2006 Jan-Feb;25(1):1-7. doi: 10.1080/15227950600701396.


Our objective was to investigate the role of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and their cellular sources in childhood asthma. We used 12 controls and 16 asthmatic children. The levels of MMP-9 and TIMP-1 in bronchoalveolar lavage (BAL) cells of asthmatic children were measured immunocytochemically. The positive level index, defined as the percentage of positive-stained cells x average optical density, was used to assess the expressing levels of MMP-9 and TIMP-1. The percentages of eosinophils and mast cells in bronchoalveolar lavage fluid (BALF) of asthmatic children were increased. Levels of MMP-9 and TIMP-1 in BAL cell of asthmatic children were increased significantly at about 30- and 35-fold relative to the controls, respectively. These results suggest that both MMP-9 and TIMP-1 contribute to tissue remodeling. MMP-9, which mediates the degradation of extracellular matrix (ECM), is increased significantly in the early or acute stage and may play a role in ECM degeneration. Excessive TIMP-1 may be synthesized following MMP-9 production when the body tries to repair the damage, which results in excessive deposition of ECM component.

MeSH terms

  • Asthma / metabolism*
  • Asthma / pathology*
  • Bronchoalveolar Lavage
  • Case-Control Studies
  • Cell Count
  • Child, Preschool
  • Eosinophils / chemistry
  • Eosinophils / pathology
  • Extracellular Matrix / chemistry
  • Extracellular Matrix / pathology
  • Female
  • Humans
  • Immunohistochemistry
  • Infant
  • Male
  • Mast Cells / chemistry
  • Mast Cells / pathology
  • Matrix Metalloproteinase 9 / analysis*
  • Matrix Metalloproteinase 9 / metabolism*
  • Tissue Inhibitor of Metalloproteinase-1 / analysis*
  • Tissue Inhibitor of Metalloproteinase-1 / metabolism*


  • Tissue Inhibitor of Metalloproteinase-1
  • Matrix Metalloproteinase 9