title: [Effect of human silicotic alveolar macrophages on expression of matrix metalloproteinase, tissue inhibitor of metalloproteinase and collagen in human lung fibroblasts].
abstract: OBJECTIVE
  To study the effect of culture supernatant of alveolar macrophage alveolar macrophages (AM) stimulated by SiO2 on the expression of matrix metalloproteinases (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and collagen of fibroblast human embryonic lung fibroblasts (HELF) in the development of silicosis fibrosis.
  
  
  METHODS
  AMs were collected from a silicotic patient by bronchoalveolar lavage and exposed to SiO2, cultured human embryo lung fibroblast were allocated into a treated group, a control group, a positive group, and a blank group. HELF was incubated with the cultured supernatant of AMs for 6, 12, 18, 24, 36, 48 h. Immunocytochemical and Western blot technology were used to detect MMP-1 and TIMP-1 expressions in HELF and collagen expression in supernatant of HELF respectively.
  
  
  RESULTS
  The supernatant of AM exposed to SiO2 significantly decreased the expressions of MMP-1 (0.0605 +/- 0.0201, 0.0519 +/- 0.0117, 0.0412 +/- 0.0105 and 0.0213 +/- 0.0106 in the treated group at 18, 24, 36 and 48 h) compared with the control group and the blank group (P < 0.05, P < 0.01) but stimulated expressions of TIMP-1 and collagen (P < 0.05, P < 0.01). The ratio of TIMP-1 to MMP-1 increased. The ratio of TIMP-1 to MMP-1 was positively correlated with the expression of collagen III (r = 0.88, P < 0.01).
  
  
  CONCLUSIONS
  Through AM mediation SiO2 can accelerate the expression of TIMP-1 and collagen, and inhibit the expression of MMP-1. The imbalance between the expression of TIMP-1 and that of MMP-1 is related with the abnormal increase in collagen III.
authors.affiliation: Department of Pathology, North China Coal Medical College, Tangshan 063000, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhu
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Liang
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Ma
authors.forename: Xian-Hua
authors.initials: XH
authors.lastname: Wang
authors.forename: Shu-Xun
authors.initials: SX
authors.lastname: Sun
mesh_terms: D002478:Cells, Cultured; D024061:Collagen Type III / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D016676:Macrophages, Alveolar / Q000187:drug effects*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D008875:Middle Aged; D012822:Silicon Dioxide / Q000633:toxicity; D012829:Silicosis / Q000473:pathology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
chemical_list: D024061:Collagen Type III; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D012822:Silicon Dioxide; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1