Related Experiment Videos
Platelet-activating factor increases the expression of metalloproteinase-9 in human bronchial epithelial cells
L Shan1, Y Nishimura, Y Kotani
1First Department of Internal Medicine, Kobe University School of Medicine, Japan.
Abstract:
Platelet-activating factor (PAF) plays an important role in the pathogenesis of bronchial asthma. To investigate the role of PAF in the maintenance and remodeling of the extracellular matrix, we evaluated the expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 from human bronchial epithelial cells after PAF treatment. Gelatin zymography of human bronchial epithelial cell-conditioned media showed major pro-matrix metalloproteinase-9 and minor pro-matrix metalloproteinase-2 expression and these expressions were totally inhibited by the metalloproteinase inhibitor EDTA. The identification of matrix metalloproteinase-9 was confirmed by Western blot analysis. Northern blotting and zymography demonstrated that PAF induced the mRNA of matrix metalloproteinase-9 from human bronchial epithelial cells and an increase in the gelatinolytic activity of pro-matrix metalloproteinase-9 but not in that of pro-matrix metalloproteinase-2. Lyso-PAF did not induce matrix metalloproteinase-9 mRNA or the gelatinolytic activity of pro-matrix metalloproteinase-9. CV6209, an receptor antagonist of PAF, reduced the increases of pro-matrix metalloproteinase-9 mRNA and gelatinolytic activity induced by PAF. Another receptor antagonist of PAF, hexanolamine PAF, did not inhibit the increases in the synthesis or release of pro-matrix metalloproteinase induced by PAF. Based on these results, we propose that matrix metalloproteinase-9 may be actively involved in the PAF-induced physiopathological remodeling in human bronchial epithelial cells.
Insights
Platelet-activating factor (PAF) induces matrix metalloproteinase-9 in bronchial epithelial cells. This suggests matrix metalloproteinase-9 plays a role in PAF-driven airway remodeling in asthma.
Area of Science:
- Pulmonary Medicine
- Cell Biology
- Biochemistry
Background:
- Platelet-activating factor (PAF) is implicated in asthma pathogenesis.
- The role of PAF in extracellular matrix remodeling in the airways is not fully understood.
Purpose of the Study:
- To investigate the role of PAF in the expression and activity of matrix metalloproteinases (MMPs) in human bronchial epithelial cells.
- To determine if PAF influences the maintenance and remodeling of the extracellular matrix.
Main Methods:
- Human bronchial epithelial cells were treated with PAF.
- Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) expression and activity were assessed using gelatin zymography and Western blotting.
- mRNA expression was analyzed by Northern blotting.
- PAF receptor antagonists (CV6209 and hexanolamine PAF) were used to investigate the PAF signaling pathway.
Main Results:
- PAF treatment significantly increased MMP-9 mRNA expression and gelatinolytic activity in bronchial epithelial cells.
- PAF did not affect MMP-2 expression or activity.
- Lyso-PAF and hexanolamine PAF did not induce MMP-9, while CV6209 inhibited PAF-induced MMP-9 increases.
- EDTA inhibited all metalloproteinase activity.
Conclusions:
- PAF induces MMP-9 expression and activity in human bronchial epithelial cells.
- MMP-9 is likely involved in the physiopathological remodeling of the extracellular matrix associated with PAF in asthma.