title: Extracellular regulated kinase/mitogen activated protein kinase is up-regulated in pulmonary emphysema and mediates matrix metalloproteinase-1 induction by cigarette smoke.
abstract: The interstitial collagenase matrix metalloprotein-ase-1 (MMP-1) is up-regulated in the lung during pulmonary emphysema. The mechanisms underlying this aberrant expression are poorly understood. Although cigarette smoking is the predominant cause of emphysema, only 15-20% of smokers develop the disease. To define the signaling pathways activated by smoke and to identify molecules responsible for emphysema-associated MMP-1 expression, we performed several in vitro and in vivo experiments. In this study, we showed that cigarette smoke directly induced MMP-1 mRNA and protein expression and increased the collagenolytic activity of human airway cells. Treatment with various chemical kinase inhibitors revealed that this response was dependent on the extracellular regulated kinase-1/2 (ERK) mitogen activated protein kinase pathway. Cigarette smoke increased phosphorylation of residues Thr-202 and Tyr-204 of ERK in airway lining cells and alveolar macrophages in mice at 10 days and 6 months of exposure. Moreover, analysis of lung tissues from emphysema patients revealed significantly increased ERK activity compared with lungs of control subjects. This ERK activity was evident in airway lining and alveolar cells. The identification of active ERK in the lungs of emphysema patients and the finding that induction of MMP-1 by cigarette smoke in pulmonary epithelial cells is ERK-dependent reveal a molecular mechanism and potential therapeutic target for excessive matrix remodeling in smokers who develop emphysema.
authors.affiliation: Department of Medicine, Divisions of Molecular and Pulmonary Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
authors.forename: Becky A
authors.initials: BA
authors.lastname: Mercer
authors.forename: Natalia
authors.initials: N
authors.lastname: Kolesnikova
authors.forename: Joshua
authors.initials: J
authors.lastname: Sonett
authors.forename: Jeanine
authors.initials: J
authors.lastname: D'Armiento
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002070:Butadienes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015151:Immunoblotting; D007150:Immunohistochemistry; D008168:Lung / Q000473:pathology; D020935:MAP Kinase Signaling System; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008856:Microscopy, Fluorescence; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D012907:Smoking; D013912:Threonine / Q000378:metabolism; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D012333:RNA, Messenger; C113580:U 0126; D013912:Threonine; D014443:Tyrosine; D006861:Hydrogen Peroxide; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020781:Matrix Metalloproteinase 1