Abstract
Urokinase plasminogen activator (uPA) and PA inhibitor type 1 (PAI-1) are elevated in acute lung injury, which is characterized by a loss of endothelial barrier function and the development of pulmonary edema. Two-chain uPA and uPA-PAI-1 complexes (1-20 nM) increased the permeability of monolayers of human pulmonary microvascular endothelial cells (PMVECs) in vitro and lung permeability in vivo. The effects of uPA-PAI-1 were abrogated by the nitric-oxide synthase (NOS) inhibitor L-NAME (N(D)-nitro-L-arginine methyl ester). Two-chain uPA (1-20 nM) and uPA-PAI-1 induced phosphorylation of endothelial NOS-Ser(1177) in PMVECs, which was followed by generation of NO and the nitrosylation and dissociation of β-catenin from VE-cadherin. uPA-induced phosphorylation of eNOS was decreased by anti-low density lipoprotein receptor-related protein-1 (LRP) antibody and an LRP antagonist, receptor-associated protein (RAP), and when binding to the uPA receptor was blocked by the isolated growth factor-like domain of uPA. uPA-induced phosphorylation of eNOS was also inhibited by the protein kinase A (PKA) inhibitor, myristoylated PKI, but was not dependent on PI3K-Akt signaling. LRP blockade and inhibition of PKA prevented uPA- and uPA-PAI-1-induced permeability of PMVEC monolayers in vitro and uPA-induced lung permeability in vivo. These studies identify a novel pathway involved in regulating PMVEC permeability and suggest the utility of uPA-based approaches that attenuate untoward permeability following acute lung injury while preserving its salutary effects on fibrinolysis and airway remodeling.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Acute Lung Injury / genetics
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Acute Lung Injury / metabolism
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Acute Lung Injury / pathology
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Animals
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Blood-Air Barrier / metabolism*
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Blood-Air Barrier / pathology
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Capillary Permeability / drug effects*
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Capillary Permeability / genetics
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Cell Line
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Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
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Cyclic AMP-Dependent Protein Kinases / genetics
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Cyclic AMP-Dependent Protein Kinases / metabolism
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Enzyme Inhibitors / pharmacology
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Fibrinolysis / drug effects
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Fibrinolysis / genetics
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Humans
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Low Density Lipoprotein Receptor-Related Protein-1 / genetics
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Low Density Lipoprotein Receptor-Related Protein-1 / metabolism*
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Mice
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Mice, Knockout
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NG-Nitroarginine Methyl Ester / pharmacology
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Nitric Oxide Synthase Type III / antagonists & inhibitors
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Nitric Oxide Synthase Type III / genetics
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Nitric Oxide Synthase Type III / metabolism*
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Phosphorylation / drug effects
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Phosphorylation / genetics
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Plasminogen Activator Inhibitor 1 / genetics
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Plasminogen Activator Inhibitor 1 / metabolism
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Plasminogen Activator Inhibitor 1 / pharmacology
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Pulmonary Edema / genetics
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Pulmonary Edema / metabolism
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Pulmonary Edema / pathology
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Respiratory Mucosa / metabolism*
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Respiratory Mucosa / pathology
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Serpin E2 / genetics
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Serpin E2 / metabolism
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Serpin E2 / pharmacology
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Urokinase-Type Plasminogen Activator / genetics
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Urokinase-Type Plasminogen Activator / metabolism
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Urokinase-Type Plasminogen Activator / pharmacology*
Substances
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Enzyme Inhibitors
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Low Density Lipoprotein Receptor-Related Protein-1
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Plasminogen Activator Inhibitor 1
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SERPINE1 protein, human
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Serpin E2
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Serpine2 protein, mouse
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Nitric Oxide Synthase Type III
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Nos3 protein, mouse
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Cyclic AMP-Dependent Protein Kinases
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Urokinase-Type Plasminogen Activator
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NG-Nitroarginine Methyl Ester