Role of ERK MAP kinases in responses of cultured human airway smooth muscle cells to IL-1beta.
We have previously reported that interleukin (IL)-1beta causes beta-adrenergic hyporesponsiveness in cultured human airway smooth muscle cells by increasing cyclooxygenase-2 (COX-2) expression and prostanoid formation. The purpose of this study was to determine whether extracellular signal-regulated kinases (ERKs) are involved in these events. Levels of phosphorylated ERK (p42 and p44) increased 8.3- and 13-fold, respectively, 15 min after treatment with IL-1beta (20 ng/ml) alone. Pretreating cells with the mitogen-activated protein kinase kinase inhibitor PD-98059 or U-126 (2 h before IL-1beta treatment) decreased ERK phosphorylation. IL-1beta (20 ng/ml for 22 h) alone caused a marked induction of COX-2 and increased basal PGE(2) release 28-fold (P < 0.001). PD-98059 (100 microM) and U-126 (10 microM) each decreased COX-2 expression when administered before IL-1beta treatment. In control cells, PD-98059 and U-126 had no effect on basal or arachidonic acid (AA; 10 microM)-stimulated PGE(2) release, but both inhibitors caused a significant decrease in bradykinin (BK; 1 microM)-stimulated PGE(2) release, consistent with a role for ERK in the activation of phospholipase A(2) by BK. In IL-1beta-treated cells, prior administration of PD-98059 caused 81, 92 and 40% decreases in basal and BK- and AA-stimulated PGE(2) release, respectively (P < 0.01), whereas administration of PD-98059 20 h after IL-1beta resulted in only 38 and 43% decreases in basal and BK-stimulated PGE(2) release, respectively (P < 0.02) and had no effect on AA-stimulated PGE(2) release. IL-1beta attenuated isoproterenol-induced decreases in human airway smooth muscle stiffness as measured by magnetic twisting cytometry, and PD-98059 or U-126 abolished this effect in a concentration-dependent manner. These results are consistent with the hypothesis that ERKs are involved early in the signal transduction pathway through which IL-1beta induces PGE(2) synthesis and beta-adrenergic hyporesponsiveness and that ERKs act by inducing COX-2 and activating phospholipase A(2).
Laporte
J D
JD
Physiology Program, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Moore
P E
PE
Abraham
J H
JH
Maksym
G N
GN
Fabry
B
B
Panettieri
R A
RA
Shore
S A
SA
D015153:Blotting, Western; D001993:Bronchodilator Agents / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D008280:Magnetics; D008565:Membrane Proteins; D008863:Microspheres; D019950:Mitogen-Activated Protein Kinase 1 / Q000276:immunology / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism*; D009130:Muscle, Smooth / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology*; D010766:Phosphorylation; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D014132:Trachea / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*
D001993:Bronchodilator Agents; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D011943:Receptors, Adrenergic, beta; D003994:Bucladesine; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; C482128:MAP2K2 protein, human; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D015232:Dinoprostone; D007545:Isoproterenol; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one