title: LPS-stimulated MUC5AC production involves Rac1-dependent MMP-9 secretion and activation in NCI-H292 cells.
abstract: Chronic obstructive pulmonary disease (COPD) is an inflammatory process characterized by airway mucus hypersecretion. Previous studies have reported that lipopolysaccharides (LPS) stimulate mucin 5AC (MUC5AC) production via epidermal growth factor receptor (EGFR) in human airway cells. Moreover, this production was shown to depend on the expression and activity of matrix metalloproteinase 9 (MMP-9), which is increased in COPD patients' serum. In the present study we investigated the signaling pathway mediating LPS-stimulated secretion and activation of MMP-9, and the regulatory effects of this pathway on the production of MUC5AC in the human airway cells NCI-H292. Using specific inhibitors, we found that LPS-stimulated cells secreted and activated MMP-9 via EGFR. Our results also indicate that signaling events downstream of EGFR involved PI3K-dependent activation of Rac1, which mediated the NADPH-generated reactive oxygen species responsible for MMP-9 secretion and activation. Finally, we observed that EGFR/PI3K/Rac1/NADPH/ROS/MMP-9 regulate MUC5AC production in LPS-challenged NCI-H292 cells.
authors.affiliation: CBRHC Research Center, Buenos Aires, Argentina.
authors.forename: Marcelo G
authors.initials: MG
authors.lastname: Binker
authors.forename: Andres A
authors.initials: AA
authors.lastname: Binker-Cosen
authors.forename: Daniel
authors.initials: D
authors.lastname: Richards
authors.forename: Brenda
authors.initials: B
authors.lastname: Oliver
authors.forename: Laura I
authors.initials: LI
authors.lastname: Cosen-Binker
mesh_terms: D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D055271:Mucin 5AC / Q000378:metabolism*; D009093:Mucus / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020545:Respiratory Mucosa / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D055271:Mucin 5AC; C107953:RAC1 protein, human; D017382:Reactive Oxygen Species; D009249:NADP; D019869:Phosphatidylinositol 3-Kinases; C512478:EGFR protein, human; D066246:ErbB Receptors; D020780:Matrix Metalloproteinase 9; D020830:rac1 GTP-Binding Protein