Stimulation of human airway epithelial cells by platelet activating factor (PAF) and arachidonic acid produces 15-hydroxyeicosatetraenoic acid (15-HETE) capable of contracting bronchial smooth muscle

1992 ◽  
Vol 5 (1) ◽  
pp. 75
Author(s):  
C.K.W. Lai ◽  
S.T. Holgate
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Platelet Activating Factor ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Hydroxyeicosatetraenoic Acid ◽  
Bronchial Smooth Muscle ◽  
Human Airway ◽  
Stimulation Of

ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells

1999 ◽  
Vol 277 (3) ◽  
pp. L465-L471 ◽  
Author(s):  
Alessandro Celi ◽  
Silvana Cianchetti ◽  
Stefano Petruzzelli ◽  
Stefano Carnevali ◽  
Filomena Baliva ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Neutrophil Adhesion ◽  
Late Time ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Human Airway ◽  
Stimulation Of ◽  
Human Airway Epithelial Cells

Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 ± 3 to 49 ± 7% (SE). A significant increase from 17 ± 4 to 39 ± 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin β-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.

scholarly journals Characterization of platelet-activating factor binding to human airway epithelial cells: modulation by fatty acids and ion-channel blockers

1994 ◽  
Vol 303 (3) ◽  
pp. 795-802 ◽  
Author(s):  
J X Kang ◽  
S F P Man ◽  
A J Hirsh ◽  
M T Clandinin
Keyword(s):  
Epithelial Cells ◽  
Channel Blocker ◽  
Platelet Activating Factor ◽  
Airway Epithelial Cells ◽  
Scatchard Analysis ◽  
Channel Blockers ◽  
Airway Epithelial ◽  
Omega 3 ◽  
Human Airway ◽  
Human Airway Epithelial Cells

Radioligand-binding studies were performed in primary cultured human airway epithelial cells with [3H]PAF to determine whether these cells express platelet-activating factor (PAF) receptors. Scatchard analysis of PAF binding data revealed a single class of PAF binding sites with Kd 1.8 +/- 0.2 nM and Bmax. 21.0 +/- 2.1 fmol/10(6) cells (13,000 receptors/cell). PAF binding increased the intracellular free Ca2+ concentration ([Ca2+]i), indicating functional PAF receptors. Palmitate (C16:0), linoleic acid (C18:2 omega 6) or eicosapentaenoic acid (C20:5 omega 3) was incubated with the cells to test the effect on PAF binding. Incorporation of each fatty acid into cellular phospholipid occurred. [3H]PAF (1 nM) binding decreased in cells supplemented with C20:5 omega 3, but increased in the cells supplemented with C16:0. Scatchard analysis revealed that the inhibition of PAF binding by supplementation with C20:5 omega 3 was due to a decrease in both affinity and number of PAF receptors. PAF-stimulated increase in [Ca2+]i was also decreased by 60% in cells supplemented with C20:5 omega 3. Verapamil, a Ca(2+)-channel blocker, and amiloride, a Na(+)-channel blocker, inhibited specific binding of [3H]PAF to the cells, with IC50 4-5 microM and 0.2 mM respectively. Diphenylamine-2-carboxylate (DPC), a Cl(-)-channel blocker, dramatically increased PAF binding to the cell in a dose-dependent manner. Scatchard analysis revealed that verapamil and amiloride decreased both binding affinity and number of PAF receptors, whereas DPC increased PAF binding sites without affecting binding affinity. These results demonstrate that human airway epithelial cells have a functional receptor for PAF and that PAF receptor binding can be modulated by exogenous fatty acids and by ion-channel blockers.

RNA interference targeted to multiple P2X receptor subtypes attenuates zinc-induced calcium entry

2005 ◽  
Vol 289 (2) ◽  
pp. C388-C396 ◽  
Author(s):  
Lihua Liang ◽  
Akos Zsembery ◽  
Erik M. Schwiebert
Keyword(s):  
Epithelial Cells ◽  
Purinergic Receptor ◽  
Airway Epithelial Cells ◽  
P2x Receptor ◽  
Receptor Subtypes ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Human Airway ◽  
Stimulation Of ◽  
Human Airway Epithelial Cells

A postulated therapeutic avenue in cystic fibrosis (CF) is activation of Ca2+-dependent Cl− channels via stimulation of Ca2+ entry from extracellular solutions independent of CFTR functional status. We have shown that extracellular zinc and ATP induce a sustained increase in cytosolic Ca2+ in human airway epithelial cells that translates into stimulation of sustained secretory Cl− transport in non-CF and CF human and mouse airway epithelial cells, cell monolayers, and nasal mucosa. On the basis of these studies, the Ca2+ entry channels most likely involved were P2X purinergic receptor channels. In the present study, molecular and biochemical data show coexpression of P2X4, P2X5, and P2X6 subtypes in non-CF (16HBE14o−) and CF (IB3-1) human bronchial epithelial cells. Other P2X receptor Ca2+ entry channel subtypes are expressed rarely or not at all in airway epithelia, epithelial cell models from other CF-relevant tissues, or vascular endothelia. Novel transient lipid transfection-mediated delivery of small interference RNA fragments specific to P2X4 and P2X6 (but not P2X5) into IB3-1 CF human airway epithelial cells inhibited extracellular zinc- and ATP-induced Ca2+ entry markedly in fura-2 Ca2+ measurements and “knocked down” protein by >65%. These data suggest that multiple P2X receptor Ca2+ entry channel subtypes are expressed in airway epithelia. P2X4 and P2X6 may coassemble on the airway surface as targets for possible therapeutics for CF independent of CFTR genotype.

scholarly journals Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells

2015 ◽  
Vol 309 (3) ◽  
pp. L237-L249 ◽  
Author(s):  
Karl Deacon ◽  
Alan J. Knox
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Cells ◽  
Airway Smooth Muscle ◽  
Airway Epithelial Cells ◽  
Airway Smooth Muscle Cells ◽  
Airway Epithelial ◽  
Human Airway Smooth Muscle ◽  
Cox 2 ◽  
Stimulation Of

Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production.

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