Induction of the plasminogen activator system by mechanical stimulation of human bronchial epithelial cells.
Mechanical stimulation of the airway epithelium, as would occur during bronchoconstriction, is a potent stimulus and can activate profibrotic pathways. We used DNA microarray technology to examine gene expression in compressed normal human bronchial epithelial cells (NHBE). Compressive stress applied continuously over an 8-h period to NHBE cells led to the upregulation of several families of genes, including a family of plasminogen-related genes that were previously not known to be regulated in this system. Real-time PCR demonstrated a peak increase in gene expression of 8.0-fold for urokinase plasminogen activator (uPA), 16.2-fold for urokinase plasminogen activator receptor (uPAR), 4.2-fold for plasminogen activator inhibitor-1 (PAI-1), and 3.9-fold for tissue plasminogen activator (tPA). Compressive stress also increased uPA protein levels in the cell lysates (112.0 versus 82.0 ng/ml, P = 0.0004), and increased uPA (4.7 versus 3.3 ng/ml, P = 0.02), uPAR (1.3 versus 0.86 ng/ml, P = 0.007), and PAI-1 (50 versus 36 ng/ml, P = 0.006) protein levels in cell culture media. Functional studies demonstrated increased urokinase-dependent plasmin generation in compression-stimulated cells (0.0090 versus 0.0033 OD/min, P = 0.03). In addition, compression led to increased activation of matrix metalloproteinase (MMP)-9 and MMP-2 in a urokinase-dependent manner. In postmortem human lung tissue, we observed an increase in epithelial uPA and uPAR immunostaining in the airways of two patients who died in status asthmaticus compared with minimal immunoreactivity noted in airways from seven lung donors without asthma. Together these observations suggest an integrated response of airway epithelial cells to mechanical stimulation, acting through the plasminogen-activating system to modify the airway microenvironment.
Chu
Eric K
EK
Brigham and Women's Hospital, Department of Pulmonary and Critical Care Medicine, Harvard School of Public Health, Physiology Program and Children's Hospital Informatics Program, Boston, Massachusetts 02115, USA. e.chu@utoronto.ca
Cheng
Jason
J
Foley
John S
JS
Mecham
Brigham H
BH
Owen
Caroline A
CA
Haley
Kathleen J
KJ
Mariani
Thomas J
TJ
Kohane
Isaac S
IS
Tschumperlin
Daniel J
DJ
Drazen
Jeffrey M
JM
D001249:Asthma / Q000378:metabolism; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D016084:Bronchoconstriction; D002460:Cell Line; D016000:Cluster Analysis; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism*; D005341:Fibrinolysin / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D008168:Lung / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010958:Plasminogen / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator; D012016:Reference Values; D013314:Stress, Mechanical; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism
C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; C051321:SERPINE1 protein, human; D010958:Plasminogen; D010959:Tissue Plasminogen Activator; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9