[The changes of expression level of matrix metalloprotease 9 and its inhibitor (TIMP-1) in murine pulmonary fibrosis model].
OBJECTIVE
To evaluate the balance between matrix metalloprotease-9 (MMP-9) and its inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1) in bleomycin-induced pulmonary fibrosis in mice.


METHODS
Pulmonary fibrosis model was induced by bleomycin in mice. The histological images of lungs were studied by HE staining. Alveolar macrophages(AMs) were separated by anti-CD68 mAbs using immunomagnetic beads(d</=50 nm). The purity of AMs was determined under microscope. Cell viability was evaluated by staining with Hoechst 33258 dye. The secreted MMP-9 and TIMP-1 were assayed in macrophage supernatants, using quantitative enzyme-linked immunosorbent assays (ELISA).


RESULTS
Collagen deposition was gradually increased in the lung tissue of mice on day 1, 3, 7, 14 and 28 after bleomycin treatment. The purity of AMs could be increased from (82.5+/-2.5)% to (99.3+/-0.7)% by mini-magnetic cell sorting system (mini-MACS, P<0.05), and the rate of living cells post-MACS was (92.5+/-1.8)% (pre-MACS (92.7+/-2.0)%, P>0.05). The concentration of MMP-9 secreted by AMs was gradually decreased on day 1, 3, 7, 14 and 28, and levels of TIMP-1 gradually increased.


CONCLUSIONS
There was an imbalance between macrophage-derived MMP-9 and TIMP-1 in bleomycin-induced pulmonary fibrosis in mice.
Li
Sheng-qing
SQ
Department of Respiratory Diseases, Xijing Hospital,Fourth Military Medical University, Xi'an 710032, China. yangzy@fmmu.edu.cn
Zhang
Jian
J
Li
Zhi-dong
ZD
Li
Huan-zhang
HZ
Qi
Hao-wen
HW
D000818:Animals; D001761:Bleomycin; D002470:Cell Survival; D016676:Macrophages, Alveolar / Q000166:cytology / Q000378:metabolism*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
D019715:Tissue Inhibitor of Metalloproteinase-1; D001761:Bleomycin; D020780:Matrix Metalloproteinase 9