Tannin stimulates arachidonic acid release from bovine tracheal epithelial cells

1996 ◽  
Vol 270 (4) ◽  
pp. L613-L618
Author(s):  
M. M. Cloutier ◽  
L. Guernsey
Keyword(s):  
Arachidonic Acid ◽  
Epithelial Cells ◽  
Pertussis Toxin ◽  
Condensed Tannin ◽  
Tracheal Epithelial Cells ◽  
Low Concentrations ◽  
Tracheal Epithelial ◽  
Acid Release ◽  
High Concentrations ◽  
Dose Dependent

Condensed tannin, isolated from cotton bracts extract (CBE), increases arachidonic acid (AA) release from rabbit alveolar macrophages and inhibits its subsequent reacylation. We determined whether tannin from CBE had any effect upon AA release in bovine tracheal epithelial cells (BTE). [14C] AA release was measured at timed intervals after addition of various concentrations of tannin to BTE cells grown to confluence in the presence of [14C] AA. Tannin caused a time- and dose-dependent release of AA from airway cells, with a maximum release occurring at 1 min in the presence of 100 micrograms/ml of tannin, and was confirmed by high-pressure liquid chromatography. The pattern of release was similar to that observed with bradykinin (2 x 10(-6) M). AA release by tannin was partially inhibited by indomethacin (10(-5) M) but not by 5,8,11,14-eicosatetraynoic acid (ETYA; 10(-5) M. Both of these drugs were effective in inhibiting bradykinin-induced AA release. In addition, AA release was not inhibited by cycloheximide. Endotoxin at 100 pg/ml and higher also caused a time-dependent release of AA that was not inhibitable by indomethacin or ETYA. Tannin-induced AA release was inhibited by pretreatment with pertussis toxin but not by neomycin, an inhibitor of phospholipase C (PLC). Neither pertussis toxin nor neomycin had any effect upon endotoxin-induced AA release. In other experiments, neither tannin nor endotoxin had any effect on [14C]AA uptake by BTE. These data demonstrate that tannin at low concentrations and endotoxin at high concentrations increase AA release by BTE cells. The AA release by tannin is partially metabolized by the cyclooxygenase pathway. We hypothesize that tannin-induced AA release is not mediated by PLC but may be mediated by other phospholipases, including PLA2.

Activation of PtdIns(4,5)P2-sensitive phospholipase C in rabbit tracheal epithelial cells

1994 ◽  
Vol 266 (2) ◽  
pp. C397-C405 ◽  
Author(s):  
C. M. Liedtke
Keyword(s):  
Epithelial Cells ◽  
Phospholipase C ◽  
Pertussis Toxin ◽  
Inositol Phosphates ◽  
Inositol Trisphosphate ◽  
Isolated Cells ◽  
Tracheal Epithelial Cells ◽  
Adrenergic Antagonist ◽  
Tracheal Epithelial

A role for phospholipase C hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] as a mechanism of alpha 2-adrenergic signal transduction in rabbit tracheal epithelial cells (tracheocytes) was investigated in isolated cells grown in in vitro culture and prelabeled with myo-[3H]inositol (3 microCi/ml) for 72 h. Breakdown of polyphosphoinositides was measured by using thin-layer chromatography to detect phosphatidylinositol, phosphatidylinositol 4-phosphate [PtdIns(4)P], and PtdIns(4,5)P2. Inositol phosphates were separated by ion-exchange column chromatography. The endogenous catecholamine l-epinephrine and alpha 2-adrenergic agonists clonidine and 1-(2,6-dichlorobenzylideneamino)guanidine (guanabenz) produced a rapid transient accumulation of inositol trisphosphate and inositol 4,5-bisphosphate and breakdown of [PtdIns(4)P] and PtdIns(4,5)P2. The alpha 2-adrenergic effects were not blocked by the beta-adrenergic antagonist DL-propranolol or by the alpha 1-adrenergic antagonists prazosin and methylurapidil but were inhibited by pertussis toxin and blocked by yohimbine, an alpha 2-adrenergic antagonist. The 50% effective concentration for guanabenz-stimulated inositol trisphosphate generation was right shifted from 0.3 to 0.9 microM by yohimbine. The results provide the first demonstration of alpha 2A-adrenergic activation of pertussis toxin-sensitive PtdIns(4,5)P2-dependent phospholipase C in mammalian tracheocytes. The findings are consistent with previous observations on alpha 2A-adrenergic-mediated activation of NaCl cotransport in these cells.

Cyclooxygenase Metabolism of Endogenous Arachidonic Acid by Cultured Human Tracheal Epithelial Cells

1989 ◽  
Vol 140 (2) ◽  
pp. 449-459 ◽  
Author(s):  
Laurie Churchill ◽  
Floyd H. Chilton ◽  
James H. Resau ◽  
Rebecca Bascom ◽  
Walter C. Hubbard ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Epithelial Cells ◽  
Tracheal Epithelial Cells ◽  
Tracheal Epithelial

scholarly journals Mycoplasma hyopneumoniae Increases Intracellular Calcium Release in Porcine Ciliated Tracheal Cells

2002 ◽  
Vol 70 (5) ◽  
pp. 2502-2506 ◽  
Author(s):  
Seung-Chun Park ◽  
Sirintorn Yibchok-Anun ◽  
Henrique Cheng ◽  
Theresa F. Young ◽  
Eileen L. Thacker ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Phospholipase C ◽  
Pertussis Toxin ◽  
Calcium Release ◽  
Mycoplasma Hyopneumoniae ◽  
Tracheal Epithelial Cells ◽  
Tracheal Epithelial ◽  
Mycoplasma Flocculare ◽  
Ciliated Epithelial Cells

ABSTRACT We investigated the effects of intact pathogenic Mycoplasma hyopneumoniae, nonpathogenic M. hyopneumoniae, and Mycoplasma flocculare on intracellular free Ca2+ concentrations ([Ca2+]i) in porcine ciliated tracheal epithelial cells. The ciliated epithelial cells had basal [Ca2+]i of 103 ± 3 nM (n = 217 cells). The [Ca2+]i increased by 250 ± 19 nM (n = 47 cells) from the basal level within 100 s of the addition of pathogenic M. hyopneumoniae strain 91-3 (300 μg/ml), and this increase lasted ∼60 s. In contrast, nonpathogenic M. hyopneumoniae and M. flocculare at concentrations of 300 μg/ml failed to increase [Ca2+]i. In Ca2+-free medium, pathogenic M. hyopneumoniae still increased [Ca2+]i in tracheal cells. Pretreatment with thapsigargin (1 μM for 30 min), which depleted the Ca2+ store in the endoplasmic reticulum, abolished the effect of M. hyoneumoniae. Pretreatment with pertussis toxin (100 ng/ml for 3 h) or U-73122 (2 μM for 100 s), an inhibitor of phospholipase C, also abolished the effect of M. hyopneumoniae. The administration of mastoparan 7, an activator of pertussis toxin-sensitive proteins Gi and Go, increased [Ca2+]i in ciliated tracheal cells. These results suggest that pathogenic M. hyopneumoniae activates receptors that are coupled to Gi or Go, which in turn activates a phospholipase C pathway, thereby releasing Ca2+ from the endoplasmic reticulum. Thus, an increase in Ca2+ may serve as a signal for the pathogenesis of M. hyopneumoniae.

scholarly journals Phospholipase A2 Functions in Pseudomonas aeruginosa- Induced Apoptosis

2006 ◽  
Vol 74 (2) ◽  
pp. 850-860 ◽  
Author(s):  
Susanne Kirschnek ◽  
Erich Gulbins
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Arachidonic Acid ◽  
Epithelial Cells ◽  
Arachidonic Acid Release ◽  
Tracheal Epithelial Cells ◽  
Host Cell Death ◽  
Cultured Epithelial Cells ◽  
Acid Release ◽  
Induced Apoptosis

ABSTRACT Pseudomonas aeruginosa, a gram-negative, facultative pathogen, causes severe and often even lethal infections in immunocompromised patients, as well as cystic fibrosis patients. We show here that a variety of P. aeruginosa strains activate phospholipase A2 (PLA2), cultured epithelial cells, and fibroblasts, resulting in increased intracellular and extracellular arachidonic acid release. The use of different PLA2 inhibitors revealed that P. aeruginosa-induced arachidonic acid release is mediated by activation of cytosolic PLA2 (cPLA2), whereas iPLA2 or sPLA2 do not seem to be involved in the response to P. aeruginosa. Likewise, the cPLA2-specific inhibitors MAFP and AACOCF3 prevented apoptosis of cultured epithelial cells upon P. aeruginosa infection, whereas inhibitors specific for iPLA2 or sPLA2 were without effect. The physiological significance of these findings is indicated by an inhibition of apoptosis in tracheal epithelial cells upon in vivo infection with P. aeruginosa. The data indicate that arachidonic acid generation by activation of cPLA2 during P. aeruginosa infection plays an important role in the induction of host cell death.

scholarly journals Rifampin Inhibits Prostaglandin E2 Production and Arachidonic Acid Release in Human Alveolar Epithelial Cells

2007 ◽  
Vol 51 (12) ◽  
pp. 4225-4230 ◽  
Author(s):  
Yael Yuhas ◽  
Inbar Azoulay-Alfaguter ◽  
Eva Berent ◽  
Shai Ashkenazi
Keyword(s):  
Arachidonic Acid ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Arachidonic Acid Release ◽  
Alveolar Epithelial ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Acid Release ◽  
Dose Dependent ◽  
Human Alveolar Epithelial Cells

ABSTRACT Rifampin, a potent antimicrobial agent, is a major drug in the treatment of tuberculosis. There is evidence that rifampin also serves as an immunomodulator. Based on findings that arachidonic acid and its metabolites are involved in the pathogeneses of Mycobacterium tuberculosis infections, we investigated whether rifampin affects prostaglandin E2 (PGE2) production in human alveolar epithelial cells stimulated with interleukin-1β. Rifampin caused a dose-dependent inhibition of PGE2 production. At doses of 100, 50, and 25 μg/ml, it inhibited PGE2 production by 75%, 59%, and 45%, respectively (P < 0.001). Regarding the mechanism involved, rifampin caused a time- and dose-dependent inhibition of arachidonic acid release from the alveolar cells. At doses of 100, 50, 25, and 10 μg/ml, it significantly inhibited the release of arachidonic acid by 93%, 64%, 58%, and 35%, respectively (P < 0.001). Rifampin did not affect the phosphorylation of cytosolic phospholipase A2 or the expression of cyclooxygenase-2. The inhibition of PGE2, and presumably other arachidonic acid products, probably contributes to the efficacy of rifampin in the treatment of tuberculosis and may explain some of its adverse effects.

scholarly journals Arachidonic acid release in rabbit neutrophils

1989 ◽  
Vol 257 (3) ◽  
pp. 633-637 ◽  
Author(s):  
W Tao ◽  
T F P Molski ◽  
R I Sha'afi
Keyword(s):  
Arachidonic Acid ◽  
Pertussis Toxin ◽  
Kinase Inhibitor ◽  
Regulatory Protein ◽  
Platelet Activating Factor ◽  
Arachidonic Acid Release ◽  
Membrane Perturbation ◽  
Acid Release ◽  
Guanine Nucleotide Regulatory Protein ◽  
Dose Dependent

[3H]Arachidonic acid is released after stimulation of rabbit neutrophils with fMet-Leu-Phe or platelet-activating factor (PAF). The release is rapid and dose-dependent, and is inhibited in phorbol 12-myristate 13-acetate (PMA)-treated rabbit neutrophils. The protein kinase C (PKC) inhibitor 1-(5-isoquinoline-sulphonyl)-2-methylpiperazine (H-7) prevents this inhibition. In addition, PMA increases arachidonic acid release in H-7-treated cells stimulated with fMet-Leu-Phe. [3H]Arachidonic acid release, but not the rise in the concentration of intracellular Ca2+, is inhibited in pertussis-toxin-treated neutrophils stimulated with PAF. The diacylglycerol kinase inhibitor R59022 increases the concentration of diacylglycerol and potentiates [3H]arachidonic acid release in neutrophils stimulated with fMet-Leu-Phe. This potentiation is not inhibited by H-7. These results suggest several points. (1) A rise in the intracellular concentration of free Ca2+ is not sufficient for arachidonic acid release in rabbit neutrophils stimulated by physiological stimuli. (2) A functional pertussis-toxin-sensitive guanine nucleotide regulatory protein and/or one or more of the changes produced by phospholipase C activation are necessary for arachidonic acid release produced by physiological stimuli. (3) Agents that stimulate PKC potentiate arachidonic acid release, and this potentiation is not inhibited by H-7. These agents produce their actions in part by direct membrane perturbation.

scholarly journals Tannin inhibits the cAMP-β-adrenergic receptor pathway in bovine tracheal epithelium

1998 ◽  
Vol 274 (2) ◽  
pp. L252-L257 ◽  
Author(s):  
Michelle M. Cloutier ◽  
Craig M. Schramm ◽  
Linda Guernsey
Keyword(s):  
Epithelial Cells ◽  
Adrenergic Receptor ◽  
Single Point ◽  
Cysteine Residues ◽  
Displacement Curve ◽  
Camp Accumulation ◽  
Receptor Density ◽  
Tracheal Epithelial Cells ◽  
Tracheal Epithelial ◽  
Dose Dependent

Tannin, isolated from cotton bracts, inhibits chloride secretion in airway epithelium. In bovine tracheal epithelial cells, tannin (25 μg/ml) blunted isoproterenol (Iso)-stimulated adenosine 3′,5′-cyclic monophosphate (cAMP) accumulation. Inhibition was time and dose dependent, with 52 ± 5% (mean ± SE, n = 6) inhibition at 60 min and 82 ± 9% ( n = 3) inhibition at 8 h. Inhibition was reversible starting at 4 h. Low-molecular-mass tannin (1,000–5,000 Da) had no effect on Iso-stimulated cAMP accumulation, whereas N-acetylcysteine, which interacts with cysteine residues, blocked the effects of tannin on Iso-stimulated cAMP accumulation. Tannin exposure (25 μg/ml for 30 min) had no effect on the dissociation constant ( K d) for [3H]dihydroalprenolol (DHA) (0.41 ± 0.03 nM, n = 3) but decreased maximal binding from 252 ± 32 to 162 ± 36 fmol/mg protein. Using single-point analysis and [3H]CGP-12177, we determined that tannin (25 μg/ml for 4 h) decreased surface β-adrenergic receptor density from 26.4 ± 4.3 ( n = 12) to 11.9 ± 3.0 fmol/mg protein and that the decrease was dose dependent. Agonist binding affinity by Iso displacement of DHA demonstrated a two-site model ( K d values = 27 ± 9 and 2,700 ± 600 nM) and a ratio of high- to low-affinity receptors of 1:1. Tannin (25 μg/ml) steepened the curve and shifted it to the right, as did Gpp(NH)p. Gpp(NH)p had no further effect on the shape or position of the displacement curve in the presence of tannin. In contrast, when polymer length was decreased by oxidation, tannin had no effect on the DHA displacement curve. These data demonstrate that tannin reversibly desensitizes bovine tracheal epithelial cells to Iso, decreases β-adrenergic receptor density, and uncouples the receptor from its stimulatory G protein. These data also suggest that the polymer length of tannin and its interaction with cysteine residues are important for these effects. These studies provide additional evidence for the role of tannin in the occupational lung disease byssinosis.

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