Th1 cytokine-induced syndecan-4 shedding by airway smooth muscle cells is dependent on mitogen-activated protein kinases

2012 ◽  
Vol 302 (7) ◽  
pp. L700-L710 ◽  
Author(s):  
Xiahui Tan ◽  
Najwa Khalil ◽  
Candice Tesarik ◽  
Karunasri Vanapalli ◽  
Viki Yaputra ◽  
...  

In asthma, airway smooth muscle (ASM) chemokine secretion can induce mast cell recruitment into the airways. The functions of the mast cell chemoattractant CXCL10, and other chemokines, are regulated by binding to heparan sulphates such as syndecan-4. This study is the first demonstration that airway smooth muscle cells (ASMC) from people with and without asthma express and shed syndecan-4 under basal conditions. Syndecan-4 shedding was enhanced by stimulation for 24 h with the Th1 cytokines interleukin-1β (IL-1β) or tumor necrosis factor-α (TNF-α), but not interferon-γ (IFNγ), nor the Th2 cytokines IL-4 and IL-13. ASMC stimulation with IL-1β, TNF-α, and IFNγ (cytomix) induced the highest level of syndecan-4 shedding. Nonasthmatic and asthmatic ASM cell-associated syndecan-4 protein expression was also increased by TNF-α or cytomix at 4–8 h, with the highest levels detected in cytomix-stimulated asthmatic cells. Cell-associated syndecan-4 levels were decreased by 24 h, whereas shedding remained elevated at 24 h, consistent with newly synthesized syndecan-4 being shed. Inhibition of ASMC matrix metalloproteinase-2 did not prevent syndecan-4 shedding, whereas inhibition of ERK MAPK activation reduced shedding from cytomix-stimulated ASMC. Although ERK inhibition had no effect on syndecan-4 mRNA levels stimulated by cytomix, it did cause an increase in cell-associated syndecan-4 levels, consistent with the shedding being inhibited. In conclusion, ASMC produce and shed syndecan-4 and although this is increased by the Th1 cytokines, the MAPK ERK only regulates shedding. ASMC syndecan-4 production during Th1 inflammatory conditions may regulate chemokine activity and mast cell recruitment to the ASM in asthma.

2006 ◽  
Vol 176 (3) ◽  
pp. 1860-1868 ◽  
Author(s):  
Amr El-Shazly ◽  
Patrick Berger ◽  
Pierre-Olivier Girodet ◽  
Olga Ousova ◽  
Michael Fayon ◽  
...  

2007 ◽  
Vol 292 (6) ◽  
pp. L1414-L1421 ◽  
Author(s):  
Yoko Osawa ◽  
Peter D. Yim ◽  
Dingbang Xu ◽  
Reynold A. Panettieri ◽  
Charles W. Emala

Tumor necrosis factor (TNF)-α is a potent inflammatory cytokine implicated in the exacerbation of asthma. Chronic exposure to TNF-α has been reported to induce G protein-coupled receptor desensitization, but adenylyl cyclase sensitization, in airway smooth muscle cells by an unknown mechanism. Cyclic AMP, which is synthesized by adenylyl cyclases in response to G protein-coupled receptor signals, is an important second messenger involved in the regulation of the airway muscle proliferation, migration, and tone. In other cell types, TNF-α receptors transactivate the EGF receptor, which activates raf-1 kinase. Further studies in transfected cells show that raf-1 kinase can phosphorylate and activate some isoforms of adenylyl cyclase. Cultured human airway smooth muscle cells were treated with TNF-α in the presence or absence of inhibitors of prostaglandin signaling, protein kinases, or Gi proteins. TNF-α caused a significant dose- (1–10 ng/ml) and time-dependent (24 and 48 h) increase in forskolin-stimulated adenylyl cyclase activity, which was abrogated by pretreatment with GW5074 (a raf-1 kinase inhibitor), was partially inhibited by an EGF receptor inhibitor, but was unaffected by pertussis toxin. TNF-α also increased phosphorylation of Ser338 on raf-1 kinase, indicative of activation. IL-1β and EGF sensitization of adenylyl cyclase activity was also sensitive to raf-1 kinase inhibition by GW5074. Taken together, these studies link two signaling pathways not previously characterized in human airway smooth muscle cells: TNF-α transactivation of the EGF receptor, with subsequent raf-1 kinase-mediated activation of adenylyl cyclase.


2014 ◽  
Vol 210 (1) ◽  
pp. S340
Author(s):  
Arij Faksh ◽  
Rodney Britt ◽  
Elizabeth Vogel ◽  
Elizabeth Baldwin ◽  
Mari Charisse Trinidad ◽  
...  

2001 ◽  
Vol 91 (3) ◽  
pp. 1467-1474 ◽  
Author(s):  
Paul E. Moore ◽  
Thomas Lahiri ◽  
Johanne D. Laporte ◽  
Trudi Church ◽  
Reynold A. Panettieri ◽  
...  

In human cultured airway smooth muscle cells, interleukin (IL)-1β increases cyclooxygenase (COX)-2 expression and PGE2 release, ultimately resulting in decreased β-adrenergic responsiveness. In this study, we aimed to determine whether tumor necrosis factor-α (TNF-α) synergizes with IL-1β in the induction of these events. TNF-α alone, at concentrations up to 10 ng/ml, had no effect on COX-2 protein expression; at concentrations as low as 0.1 ng/ml, it significantly enhanced the ability of IL-1β (0.2 ng/ml) to induce COX-2 and to increase PGE2 release. IL-1β and TNF-α in combination also significantly enhanced COX-2 promoter activity, indicating that synergism between the cytokines is mediated at the level of gene transcription. Although IL-1β and TNF-α each increased nuclear factor-κB activation and induced extracellular regulated kinase and p38 phosphorylation, combined administration of the cytokines did not enhance either nuclear factor-κB or mitogen-activated protein kinase activation. Combined administration of IL-1β (0.2 ng/ml) and TNF-α (0.1 or 1.0 ng/ml) reduced the ability of isoproterenol to decrease human airway smooth muscle cell stiffness, as measured by magnetic twisting cytometry, even though individually these cytokines, at these concentrations, had no effect on isoproterenol responses. Treatment with the selective COX-2 inhibitor NS-398 abolished the synergistic effects of TNF-α and IL-1β on β-adrenergic responsiveness. Our results indicate that low concentrations of IL-1β and TNF-α synergize to promote β-adrenergic hyporesponsiveness and that effects on COX-2 expression and PGE2 are responsible for these events. The data suggest that the simultaneous release in the airway, of even very small amounts of cytokines, can have important functional consequences.


2008 ◽  
Vol 9 (1) ◽  
Author(s):  
Krishnaswamy G Tirumurugaan ◽  
Bit Na Kang ◽  
Reynold A Panettieri ◽  
Douglas N Foster ◽  
Timothy F Walseth ◽  
...  

2002 ◽  
Vol 282 (2) ◽  
pp. L197-L206 ◽  
Author(s):  
James K. Brown ◽  
Cary A. Jones ◽  
Leeann A. Rooney ◽  
George H. Caughey ◽  
Ian P. Hall

We reported previously that mast cell tryptase is a growth factor for dog tracheal smooth muscle cells. The goals of our current experiments were to determine if tryptase also is mitogenic in cultured human airway smooth muscle cells, to compare its strength as a growth factor with that of other mitogenic serine proteases, and to determine whether its proteolytic actions are required for mitogenesis. Highly purified preparations of human lung β-tryptase (1–30 nM) caused dose-dependent increases in DNA synthesis in human airway smooth muscle cells. Maximum tryptase-induced increases in DNA synthesis far exceeded those occurring in response to coagulation cascade proteases, such as thrombin, factor Xa, or factor XII, or to other mast cell proteases, such as chymase or mastin. Irreversibly abolishing tryptase's catalytic activity did not alter its effects on increases in DNA synthesis. We conclude that β-tryptase is a potent mitogenic serine protease in cultured human airway smooth muscle cells. However, its growth stimulatory effects in these cells occur predominantly via nonproteolytic actions.


1999 ◽  
Vol 276 (3) ◽  
pp. L405-L411 ◽  
Author(s):  
Kunihisa Hotta ◽  
Charles W. Emala ◽  
Carol A. Hirshman

Chronic inflammation is a characteristic feature of asthma. Multiple inflammatory mediators are released within the asthmatic lung, some of which may have detrimental effects on signal transduction pathways in airway smooth muscle. The effects of tumor necrosis factor (TNF)-α on the expression and function of muscarinic receptors and guanine nucleotide-binding protein (G protein) α-subunits were examined in human airway smooth muscle cells. Cultured human airway smooth muscle cells were incubated in serum-free culture medium for 72 h in the presence and absence of 10 ng/ml of TNF-α, after which the cells were lysed and subjected to electrophoresis and Gαi-2, Gqα, and Gsα protein subunits were detected by immunoblot analysis with specific antisera. TNF-α treatment for 72 h significantly increased the expression of Gαi-2 and Gqα proteins and enhanced carbachol (10−7 M)-mediated inhibition of adenylyl cyclase activity and inositol phosphate synthesis. These data provide new evidence demonstrating that TNF-α not only increases expression of Gαi-2 and Gqα proteins but also augments the associated signal transduction pathways that would facilitate increased tone of airway smooth muscle.


2004 ◽  
Vol 287 (6) ◽  
pp. L1230-L1240 ◽  
Author(s):  
Maria B. Sukkar ◽  
Razao Issa ◽  
Shaoping Xie ◽  
Ute Oltmanns ◽  
Robert Newton ◽  
...  

Chemokine synthesis by airway smooth muscle cells (ASMC) may be an important process underlying inflammatory cell recruitment in airway inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD). Fractalkine (FKN) is a recently described CX3C chemokine that has dual functions, serving as both a cell adhesion molecule and a chemoattractant for monocytes and T cells, expressing its unique receptor, CX3CR1. We investigated FKN expression by human ASMC in response to the proinflammatory cytokines IL-1β, TNF-α, and IFN-γ, the T helper 2-type cytokines IL-4, IL-10, and IL-13, and the fibrogenic cytokine transforming growth factor (TGF)-β. Neither of these cytokines alone had any significant effect on ASMC FKN production. Combined stimulation with IFN-γ and TNF-α induced FKN mRNA and protein expression in a time- and concentration-dependent manner. TGF-β had a significant inhibitory effect on cytokine-induced FKN mRNA and protein expression. Dexamethasone (10−8–10−6 M) significantly upregulated cytokine-induced FKN mRNA and protein expression. Finally, we used selective inhibitors of the mitogen-activated protein kinases c-Jun NH2-terminal kinase (JNK) (SP-610025), p38 (SB-203580), and extracellular signal-regulated kinase (PD-98095) to investigate their role in FKN production. SP-610025 (25 μM) and SB-203580 (20 μM), but not PD-98095, significantly attenuated cytokine-induced FKN protein synthesis. IFN-γ- and TNF-α-induced JNK phosphorylation remained unaltered in the presence of TGF-β but was inhibited by dexamethasone, indicating that JNK is not involved in TGF-β- or dexamethasone-mediated regulation of FKN production. In summary, FKN production by human ASMC in vitro is regulated by inflammatory and anti-inflammatory factors.


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