[Tumor necrosis factor alpha-induced expression and activity of alveolar macrophages matrix metalloproteinase-9 in chronic obstructive pulmonary disease].
OBJECTIVE
To explore the expression and activity of matrix metalloproteinase-9 (MMP-9) from alveolar macrophages (AMs) induced by tumor necrosis factor-alpha (TNFalpha) in patients with chronic obstructive pulmonary disease (COPD), and therefore to study the possible mechanisms.


METHODS
AMs were collected from bronchoalveolar lavage fluid from patients with COPD, and then were stimulated for 24 h with TNFalpha at concentrations of 0.1 ng/ml, 1 ng/ml, 5 ng/ml, 10 ng/ml, and 20 ng/ml, respectively. The gene expression level of MMP-9 induced by TNFalpha was detected by semi-quantitative RT-PCR, and MMP-9 activity was measured by zymography. NF-kappaB activity was detected by electrophoretic mobility shift assay.


RESULTS
In unstimulated AMs, the densitometry unit rate of MMP-9 mRNA to beta-actin mRNA was 0.1826 +/- 0.0084. When AMs were stimulated by TNFalpha at concentrations of 0.1 ng/ml, 1 ng/ml, 5 ng/ml, 10 ng/ml, and 20 ng/ml, the densitometry unit rates of MMP-9 mRNA to beta-actin mRNA were 0.4279 +/- 0.0204, 0.5431 +/- 0.0058, 0.6185 +/- 0.0208, 0.6859 +/- 0.0080, and 0.7784 +/- 0.0208, respectively. In unstimulated AMs, the densitometry unit of active MMP-9 was 10 227 +/- 738, but when AMs were stimulated by TNFalpha at concentrations of 0.1 ng/ml, 1 ng/ml, 5 ng/ml, 10 ng/ml, and 20 ng/ml, the densitometry units of active MMP-9 were 40,528 +/- 974, 113,741 +/- 4547, 190,696 +/- 4032, 309,505 +/- 7639, and 427,305 +/- 9145, respectively. NF-kappaB activity was significantly elevated after AMs were stimulated by TNFalpha at the concentration of 10 ng/ml (P < 0.05).


CONCLUSIONS
The expression and activity of MMP-9 can be induced by TNFalpha, and the induction was possibly related with the NF-kappaB-mediated signal transduction pathway.
Li
Ya-qing
YQ
Department of Respiratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhang
Zhen-xiang
ZX
Xu
Yong-jian
YJ
Xiong
Sheng-dao
SD
Yang
Zhao
Z
Ni
Wang
W
Chen
Shi-xin
SX
Ma
Dan
D
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016676:Macrophages, Alveolar / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism*; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D016328:NF-kappa B; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9