title: [Changes of matrix metalloproteinase 2,9 and tissue inhibitor of metalloproteinase 1, 2, 3 expression level in aged rat lung].
abstract: OBJECTIVE
  To investigate the underlying mechanism of age related increase of pulmonary fibrosis incidence
  
  
  METHODS
  The levels of pulmonary collagen and TGF-beta1 protein, MMP2,9 mRNA and TIMP 1,2,3 mRNA expression were measured by ELISA and realtime PCR.
  
  
  RESULTS
  As compared with adult rats [(756 +/- 160) pg/g vs (1 000 +/- 246) pg/g, P<0.05] the aged rats had more extracellular matrix components, increased TGF-beta1 protein level, lower (3.15 +/- 1.76 vs 0.17 +/- 0.13, P<0.01) MMP2 mRNA expression and TIMP 1,2,3 mRNA expressions (TIMP1 2.00 +/- 1.74 vs 0.11 +/- 0.06,TIMP2 7.60 +/- 2.51 vs 2.69 +/- 1.76, TIMP3 1.32 +/- 0.46 vs 0.29 +/- 0.16, P<0.01). No difference was observed in MMP9 (1.66 +/- 0.67 vs 1.74 +/- 0.87, P>0.05) mRNA expression.
  
  
  CONCLUSIONS
  elevation in TGF-beta1 protein level, changes in the expression of MMP2/9 and decreased expression of TIMPS mRNA could be the underlying mechanism of age related increase of pulmonary incidence.
authors.affiliation: Department of Geriatris, Peking University First Hospital, Beijing 100034, China. zhaozhijie1972@yahoo.com.cn
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Zhao
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Liu
authors.forename: Guo-Peng
authors.initials: GP
authors.lastname: Zhou
mesh_terms: D000375:Aging; D000818:Animals; D005260:Female; D015870:Gene Expression; D008168:Lung / Q000378:metabolism*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000378:metabolism
chemical_list: C576839:TIMP1 protein, rat; D019715:Tissue Inhibitor of Metalloproteinase-1; D019717:Tissue Inhibitor of Metalloproteinase-3; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat