PGE2 release by bradykinin in human airway smooth muscle cells: involvement of cyclooxygenase-2 induction

1997 ◽  
Vol 273 (6) ◽  
pp. L1132-L1140 ◽  
Author(s):  
Linhua Pang ◽  
Alan J. Knox

Prostanoids may be involved in bradykinin (BK)-induced bronchoconstriction in asthma. We investigated whether cyclooxygenase (COX)-2 induction was involved in prostaglandin (PG) E2 release by BK in cultured human airway smooth muscle (ASM) cells and analyzed the BK receptor subtypes responsible. BK stimulated PGE2release, COX activity, and COX-2 induction in a concentration- and time-dependent manner. It also time dependently enhanced arachidonic acid release. In short-term (15-min) experiments, BK stimulated PGE2 generation but did not increase COX activity or induce COX-2. In long-term (4-h) experiments, BK enhanced PGE2 release and COX activity and induced COX-2. The long-term responses were inhibited by the protein synthesis inhibitors cycloheximide and actinomycin D and the steroid dexamethasone. The effects of BK were mimicked by the B2-receptor agonist [Tyr(Me)8]BK, whereas the B1 agonist des-Arg9-BK was weakly effective at high concentrations. The B2antagonist HOE-140 potently inhibited all the effects, but the B1 antagonist des-Arg9,(Leu8)-BK was inactive. This study is the first to demonstrate that BK can induce COX-2. Conversion of increased arachidonic acid release to PGE2 by COX-1 is mainly involved in the short-term effect, whereas B2 receptor-related COX-2 induction is important in the long-term PGE2 release.

1998 ◽  
Vol 275 (3) ◽  
pp. L491-L501 ◽  
Author(s):  
Johanne D. Laporte ◽  
Paul E. Moore ◽  
Reynold A. Panettieri ◽  
Winfried Moeller ◽  
Joachim Heyder ◽  
...  

We have previously reported that pretreatment of cultured human airway smooth muscle (HASM) cells with interleukin-1β (IL-1β) results in decreased β-adrenergic responsiveness. The purpose of this study was to determine whether prostanoids released as a result of cyclooxygenase-2 (COX-2) induction by IL-1β contribute to this effect of the cytokine. Confluent serum-deprived HASM cells were studied in passages 4–7. IL-1β (20 ng/ml for 22 h) reduced the ability of the β-agonist isoproterenol (Iso) to decrease stiffness of HASM cells as measured by magnetic twisting cytometry. The effect of IL-1β on Iso-induced changes in cell stiffness was abolished by nonselective [indomethacin (Indo), 10−6 M] and selective (NS-398, 10−5 M) COX-2 inhibitors. Indo and NS-398 also inhibited both the increased basal cAMP and the decreases in Iso-stimulated cAMP production induced by IL-1β. IL-1β (20 ng/ml for 22 h) caused an increase in both basal (15-fold) and arachidonic acid (AA)-stimulated (10-fold) PGE2 release. Indo blocked basal and AA-stimulated PGE2 release in both control and IL-1β-treated cells. NS-398 also markedly reduced basal and AA-stimulated PGE2release in IL-1β-treated cells but had no significant effect on AA-stimulated PGE2 release in control cells. Western blot analysis confirmed the induction of COX-2 by IL-1β. Exogenously administered PGE2(10−7 M, 22 h) caused a significant reduction in the ability of Iso to decrease cell stiffness, mimicking the effects of IL-1β. Cycloheximide (10 μg/ml for 24 h), an inhibitor of protein synthesis, also abolished the effects of IL-1β on Iso-induced cell stiffness changes and cAMP formation. In summary, our results indicate that IL-1β significantly increases prostanoid release by HASM cells as a result of increased COX-2 expression. The prostanoids appear to contribute to β-adrenergic hyporesponsiveness, perhaps by heterologous desensitization of the β2 receptor.


2001 ◽  
Vol 280 (6) ◽  
pp. L1225-L1232 ◽  
Author(s):  
Thomas Lahiri ◽  
Johanne D. Laporte ◽  
Paul E. Moore ◽  
Reynold A. Panettieri ◽  
Stephanie A. Shore

Interleukin (IL)-1β induces cyclooxygenase (COX)-2 expression and prostanoid formation in cultured human airway smooth muscle (HASM) cells. In other cell types, IL-6 family cytokines induce COX-2 or augment IL-1β-induced COX-2 expression. The purpose of this study was to determine whether IL-6 family cytokines were involved in COX-2 expression in HASM cells. RT-PCR was used to demonstrate that the necessary receptor components for IL-6-type cytokine binding are expressed in HASM cells. IL-6 and oncostatin M (OSM) each caused a dose-dependent phosphorylation of signal transducer and activator of transcription-3, whereas IL-11 did not. IL-6, IL-11, and OSM alone had no effect on COX-2 expression. However, OSM caused dose-dependent augmentation of COX-2 expression and prostaglandin (PG) E2release induced by IL-1β. In contrast, IL-6 and IL-11 did not alter IL-1β-induced COX-2 expression. IL-6 did increase IL-1β-induced PGE2formation in unstimulated cells but not in cells stimulated with arachidonic acid (AA; 10−5M), suggesting that IL-6 effects were mediated at the level of AA release. Our results indicate that IL-6 and OSM are capable of inducing signaling in HASM cells. In addition, OSM and IL-1β synergistically cause COX-2 expression and PGE2release.


2000 ◽  
Vol 279 (1) ◽  
pp. L201-L207 ◽  
Author(s):  
Choong Yi Fong ◽  
Linhua Pang ◽  
Elaine Holland ◽  
Alan J. Knox

We have recently shown that endogenous prostanoids are critical in bradykinin-stimulated interleukin (IL)-8 release from human airway smooth muscle (ASM) cells. In this study, we tested the ability of transforming growth factor (TGF)-β1 to stimulate IL-8 release, cyclooxygenase (COX)-2 expression and PGE2 generation in cultured human ASM cells and explored the role of COX products and COX-2 induction on IL-8 release. TGF-β1 stimulated IL-8 release, COX-2 induction, and PGE2 generation in a concentration- and time-dependent manner. Maximal IL-8 release was achieved with 10 ng/ml of TGF-β1 after 16 h of incubation, which was inhibited by the transcription inhibitor actinomycin D and the corticosteroid dexamethasone but was not affected by the nonselective COX inhibitor indomethacin and the selective COX-2 inhibitor NS-398 despite their inhibition on TGF-β1-induced PGE2 release. These results show for the first time that TGF-β1 stimulates IL-8 release, COX-2 induction, and PGE2 generation in human ASM cells and that PGE2 generation is not critical for TGF-β1-induced IL-8 release. These findings suggest that TGF-β1 may play an important role in the pathophysiology of asthma.


1983 ◽  
Vol 61 (7) ◽  
pp. 705-713 ◽  
Author(s):  
C. Davis ◽  
T. R. Jones ◽  
E. E. Daniel

This investigation was carried out to study allergic contraction of passively sensitized human airway smooth muscle in response to specific antigen challenge. We attempted to determine the role played by histamine, slow reaction substances (SRSs), and cyclooxygenase products in the mediation of this response in tracheal smooth muscle. Tissues were passively sensitized with serum from ragweed-sensitive patients (15 h, 4 °C). Subsequent challenge with ragweed antigen produced a slowly developing contraction. The peak contraction to a dose producing a maximal response was 37 ± 6% of the carbachol maximum. Mepyramine (5 × 10−6 M) did not alter the contraction. Methylprednisolone (2 × 10−5 M) attenuated the response to antigen but had no significant effect on the contractile response to arachidonic acid. Indomethacin (5.6–28 × 10−6 M) enhanced the peak antigen-induced contractions by 25 ± 11% whereas 5, 8, 11, 14-eicosatetraynoic acid (6.4 × 10−5 M) selectively attenuated the antigen-induced contraction by 86 ± 12%. Nordihydroguarietic acid (6–12 × 10−6 M) attenuated both the antigen plus arachidonate induced responses. FPL-55712 (1–2 × 10−6 M) antagonized the contractions to antigen. Compound 48/80 and goat antihuman immunoglobulin E produced similar slowly developing contractions in sensitized and in some nonsensitized tissues. These responses, except for an early component of the response to 48/80, were independent of histamine and were reversed by FPL-55712. These findings suggest that arachidonic acid metabolites mediate (slow reacting substances) and modulate (prostaglandins) allergic contraction of human airway smooth muscle while any histamine released contributes little or nothing to the contraction in the larger airways.


1999 ◽  
Vol 277 (5) ◽  
pp. L943-L951 ◽  
Author(s):  
Johanne D. Laporte ◽  
Paul E. Moore ◽  
Joseph H. Abraham ◽  
Geoffrey N. Maksym ◽  
Ben Fabry ◽  
...  

We have previously reported that interleukin (IL)-1β causes β-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-1β (20 ng/ml) alone. Pretreating cells with the mitogen-activated protein kinase kinase inhibitor PD-98059 or U-126 (2 h before IL-1β treatment) decreased ERK phosphorylation. IL-1β (20 ng/ml for 22 h) alone caused a marked induction of COX-2 and increased basal PGE2 release 28-fold ( P < 0.001). PD-98059 (100 μM) and U-126 (10 μM) each decreased COX-2 expression when administered before IL-1β treatment. In control cells, PD-98059 and U-126 had no effect on basal or arachidonic acid (AA; 10 μM)-stimulated PGE2 release, but both inhibitors caused a significant decrease in bradykinin (BK; 1 μM)-stimulated PGE2 release, consistent with a role for ERK in the activation of phospholipase A2 by BK. In IL-1β-treated cells, prior administration of PD-98059 caused 81, 92 and 40% decreases in basal and BK- and AA-stimulated PGE2 release, respectively ( P < 0.01), whereas administration of PD-98059 20 h after IL-1β resulted in only 38 and 43% decreases in basal and BK-stimulated PGE2release, respectively ( P < 0.02) and had no effect on AA-stimulated PGE2 release. IL-1β 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-1β induces PGE2 synthesis and β-adrenergic hyporesponsiveness and that ERKs act by inducing COX-2 and activating phospholipase A2.


1998 ◽  
Vol 275 (2) ◽  
pp. L322-L329 ◽  
Author(s):  
Linhua Pang ◽  
Elaine Holland ◽  
Alan J. Knox

Interleukin (IL)-1β impairs human airway smooth muscle (ASM) cell cAMP responses to isoproterenol (Iso). We investigated if bradykinin (BK) could cause a similar effect and the role of cyclooxygenase (COX) products in this event, since we have recently reported that BK, like IL-1β, also causes COX-2 induction and prostanoid release in human ASM cells. BK pretreatment significantly attenuated Iso-induced cAMP generation in a time- and concentration-dependent manner. cAMP generation by prostaglandin (PG) E2but not by forskolin was also impaired. The COX inhibitor indomethacin completely prevented the impairment, whereas the selective COX-2 inhibitors NS-398 and nimesulide, protein synthesis inhibitors cycloheximide and actinomycin D, and steroid dexamethasone were all partially effective. The impairment was mimicked by the B2agonist [Tyr(Me)8]BK, the Ca2+ionophore A-23187, and PGE2and prevented by the B2antagonist HOE-140, but anti-IL-1β serum was ineffective. The results indicate that BK impairs human ASM cell responses to Iso, and the effect is largely mediated by B2receptor-related COX product release via both COX isoforms and is independent of IL-1β.


2014 ◽  
Vol 307 (9) ◽  
pp. L727-L734 ◽  
Author(s):  
Brian S. Comer ◽  
Blanca Camoretti-Mercado ◽  
Paul C. Kogut ◽  
Andrew J. Halayko ◽  
Julian Solway ◽  
...  

MicroRNA (miR)-146a and miR-146b are negative regulators of inflammatory gene expression in lung fibroblasts, epithelial cells, monocytes, and endothelial cells. The abundance of cyclooxygenase-2 (COX-2) and IL-1β is negatively regulated by the miR-146 family, suggesting miR-146a and/or miR-146b might modulate inflammatory mediator expression in airway smooth muscle thereby contributing to pathogenesis of asthma. To test this idea we compared miR-146a and miR-146b expression in human airway smooth muscle cells (hASMCs) from nonasthmatic and asthmatic subjects treated with cytomix (IL-1β, TNF-α, and IFNγ) and examined the miRNAs' effects on COX-2 and IL-1β expression. We found that cytomix treatment elevated miR-146a and miR-146b abundance. Induction with cytomix was greater than induction with individual cytokines, and asthmatic cells exhibited higher levels of miR-146a expression following cytomix treatment than nonasthmatic cells. Transfection of miR-146a or miR-146b mimics reduced COX-2 and IL-1β expression. A miR-146a inhibitor increased COX-2 and IL-1β expression, but a miR-146b inhibitor was ineffective. Repression of COX-2 and IL-1β expression by miR-146a correlated with reduced abundance of the RNA-binding protein human antigen R. These results demonstrate that miR-146a and miR-146b expression is inducible in hASMCs by proinflammatory cytokines and that miR-146a expression is greater in asthmatic cells. Both miR-146a and miR-146b can negatively regulate COX-2 and IL-1β expression at pharmacological levels, but loss-of-function studies showed that only miR-146a is an endogenous negative regulator in hASMCs. The results suggest miR-146 mimics may be an attractive candidate for further preclinical studies as an anti-inflammatory treatment of asthma.


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