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Fabi F, Calabrese R, Stati T, del Basso P. Nitric oxide (NO) modulation of PAF-induced cardiopulmonary action: interaction between NO synthase and cyclo-oxygenase-2 pathways. Br J Pharmacol 2001; 134:777-88. [PMID: 11606318 PMCID: PMC1573004 DOI: 10.1038/sj.bjp.0704311] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
1. To further investigate into the mechanisms of PAF-induced cardiopulmonary actions, we examined the effects of the nitric oxide synthase (NOS) inhibitor L-N(omega)-nitro-L-arginine (L-NNA), of the specific cyclooxygenase-2 (COX-2) inhibitor NS 398, and of the combined presence of both COX and NOS inhibitors on the PAF responses in the heart lung preparation of guinea-pig (HLP). 2. In HLPs perfused with homologous blood, dose-response curves for the haemodynamic and bronchial effects of PAF (1 - 32 ng) were carried out in the absence or presence of L-NNA (200 microM). L-NNA caused an increase in the resting pulmonary arterial pressure (PAP) without affecting the other basal values, and strongly potentiated the bronchoconstriction and pulmonary hypertension elicited by PAF. An enhancement of the PAF-induced actions on right atrial pressure (RAP) and cardiac output (CO) was also observed. All the effects of L-NNA were antagonized by L-arginine (2 mM). 3. The presence of L-NNA in the perfusing blood of HLPs failed to affect the pulmonary hypertensive and bronchoconstrictor responses induced by the thromboxane A(2) mimetic U46619 (0.05 - 1.6 microg), 5-hydroxytryptamine (0.1 - 1.6 microg), and histamine (0.1 - 1.6 microg), thus suggesting that these PAF secondary mediators are not responsible for the hyper-responsiveness to PAF induced by L-NNA. 4. Blocking COX-2 pathway with NS 398 (15 - 30 microM) did not alter the cardiopulmonary resting variables. However, a reduction of the PAF-mediated pulmonary hypertension, but not of bronchoconstriction, was observed. When L-NNA was added to the perfusing medium of HLPs pre-treated with NS 398 or with indomethacin (15 microM), the basal PAP values were enhanced. However, in the combined presence of COX and NOS inhibitors, only a slight increase in the hypertensive responses to the highest doses of PAF was observed, whereas the PAF mediated actions at bronchial and cardiac level were unaffected. 5. This study indicates that (i) the cardiopulmonary actions induced by PAF are specifically modulated by endogenous NO through the NOS pathway, and (ii) COX-2 isoform is involved in the pulmonary hypertensive, but not bronchoconstrictor, effects of PAF. Furthermore, an interaction between PAF stimulated COX, particularly COX-2, and NOS pathways appears to take a functional role at both bronchial and cardiovascular level.
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Affiliation(s)
- Fulvia Fabi
- Laboratory of Pharmacology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Roberto Calabrese
- Laboratory of Pharmacology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Tonino Stati
- Laboratory of Pharmacology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Paola del Basso
- Laboratory of Pharmacology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
- Author for correspondence:
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102
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Muijsers RBR, van Ark I, Folkerts G, Koster AS, van Oosterhout AJM, Postma DS, Nijkamp FP. Apocynin and 1400 W prevents airway hyperresponsiveness during allergic reactions in mice. Br J Pharmacol 2001; 134:434-40. [PMID: 11564663 PMCID: PMC1572946 DOI: 10.1038/sj.bjp.0704235] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The contribution of reactive nitrogen species to the development of airway hyperresponsiveness in a mouse model of allergic inflammation was investigated by the use of selective inhibitors of nitric oxide and superoxide formation. 2. Sensitized mice, repeatedly challenged with ovalbumin showed a significant (P<0.001, n=9) increase in airway responsiveness measured using whole body plethysmography. This hyperresponsiveness was accompanied by an influx of eosinophils into the airway lumen and increased levels of ovalbumin-specific serum IgE. 3. Treatment of mice with the iNOS inhibitor 1400 W or the NADPH-oxidase inhibitor apocynin did not significantly alter cellular influx into the airway lumen nor serum ovalbumin specific IgE. In contrast, apocynin as well as 1400 W inhibited ovalbumin-induced airway hyperresponsiveness (P<0.001 and P<0.05 respectively, n=9). Furthermore, the airways of allergen challenged animals showed clear 3-nitrotyrosine staining, which was mainly located in eosinophils. Remarkably, treatment with apocynin or 1400 W did not alter 3-nitrotyrosine staining. 4. These data suggest that the development of airway hyperresponsiveness during the airway inflammation upon ovalbumin challenge is dependent on the release of both superoxide and nitric oxide and is therefore likely to be dependent on reactive nitrogen species. This mechanism, however, is not reflected by 3-nitrotyrosine formation in the airways.
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Affiliation(s)
- Richard B R Muijsers
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
| | - Ingrid van Ark
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
| | - Gert Folkerts
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
- Author for correspondence:
| | - Andries S Koster
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
| | - Antoon J M van Oosterhout
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
| | - Dirkje S Postma
- Department of Pulmonology, University Hospital Groningen, Oostersingel 59, 9700RB Groningen, The Netherlands
| | - Frans P Nijkamp
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
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103
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El-Mowafy AM, Biggs DF. ET(B) receptor activates adenylyl cyclase via a c-PLA(2)-dependent mechanism: a novel counterregulatory mechanism of ET-induced contraction in airway smooth muscle. Biochem Biophys Res Commun 2001; 286:388-93. [PMID: 11500050 DOI: 10.1006/bbrc.2001.5389] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelin-1 (ET-1) contracted the rabbit tracheal smooth muscle (RTSM), yielding a bell-shaped tension-concentration curve. Moreover, ET-1 induced concentration- and time-dependent increases in cAMP concentrations in RTSM (EC(50), 58 nM; t(1/2), 2.4 min). Pretreatment with the AC inhibitors, SQ-22536, or 2'-5'-dideoxyadenosine, enhanced contraction to ET-1 and converted its bell-shaped tension curve into a sigmoidal one, but left contraction to carbachol and KCl unaltered. The potent ET(B)-receptor agonists, ET-3 or sarafotoxin-c, mimicked ET-1's effects on cAMP levels (EC(50) values 55 and 50 nM). Further, cAMP formation by ETs was inhibited by BQ-788 (selective ET(B) receptor blocker; IC(50), 8 nM), but not by BQ-610 (selective ET(A) receptor blocker). Removal of the epithelium did not prevent ET-induced increases in cAMP levels. Unlike isoproterenol, ETs failed to activate AC in membrane fractions from RTSM. In intact RTSM, the c-PLA(2) inhibitor, AACOCF3, and the cyclooxygenase inhibitor, indomethacin, blocked ET-induced increases in cAMP levels. These findings reveal a novel, nonepithelial, c-PLA(2)-mediated, regulatory mechanism downstream from ET(B) receptors.
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Affiliation(s)
- A M El-Mowafy
- Department of Applied Therapeutics, Kuwait University, Safat, 13110, Kuwait.
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104
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Ten Broeke R, Folkerts G, Leusink-Muis T, Van der Linde HJ, Villain M, Manion MK, De Clerck F, Blalock JE, Nijkamp FP. Calcium sensors as new therapeutic targets for airway hyperresponsiveness and asthma. FASEB J 2001; 15:1831-3. [PMID: 11481245 DOI: 10.1096/fj.01-0018fje] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- R Ten Broeke
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3508 TB Utrecht, The Netherlands
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105
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Ricciardolo FL, Timmers MC, Geppetti P, van Schadewijk A, Brahim JJ, Sont JK, de Gouw HW, Hiemstra PS, van Krieken JH, Sterk PJ. Allergen-induced impairment of bronchoprotective nitric oxide synthesis in asthma. J Allergy Clin Immunol 2001; 108:198-204. [PMID: 11496234 DOI: 10.1067/mai.2001.116572] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Endogenous nitric oxide protects against airway hyperresponsiveness (AHR) to bradykinin in mild asthma, whereas AHR to bradykinin is enhanced by inhaled allergens. OBJECTIVE Hypothesizing that allergen exposure impairs bronchoprotective nitric oxide within the airways, we studied the effect of the inhaled nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on AHR to bradykinin before and after allergen challenge in 10 subjects with atopic asthma. METHODS The study consisted of 3 periods (1 diluent and 2 allergen challenges). AHR to bradykinin (PD(20)BK) was examined before and 48 hours after allergen challenge, both after double-blinded pretreatment with L-NMMA or placebo. The accompanying expression of the various NOS isoforms (ecNOS, nNOS, and iNOS) was examined by means of immunohistochemistry in bronchial biopsies obtained after diluent and allergen challenge. RESULTS After placebo, AHR to BK worsened after allergen challenge in comparison with before allergen challenge (PD(20)BK, 70.8 nmol [range, 6.3-331] and 257 nmol [35.5-2041], respectively; P =.0004). After L-NMMA, preallergen and postallergen PD(20)BK values (50.1 nmol [1.8-200] vs 52.5 nmol [6.9-204]; P =.88) were similarly reduced (P <.01) and not different from the postplacebo/postallergen value (P >.05). After allergen challenge, the intensity of staining in bronchial epithelium decreased for ecNOS (P =.03) and increased for iNOS (P =.009). These changes in immunostaining were correlated with the accompanying worsening in AHR to BK (R(s) = -0.66 and 0.71; P <.04). CONCLUSIONS These data indicate that allergen exposure in asthma induces increased airway hyperresponsiveness to bradykinin through impaired release of bronchoprotective nitric oxide associated with downregulation of ecNOS. This suggests that new therapeutic strategies towards restoring the balance among the NOS isoforms during asthma exacerbations are warranted.
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Affiliation(s)
- F L Ricciardolo
- Department of Pulmonology, Leiden University Medical Center, The Netherlands
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106
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Folkerts G, Kloek J, Geppetti P, Van der Linde HJ, Nijkamp FP. Factors that determine acetylcholine responsiveness of guinea pig tracheal tubes. Eur J Pharmacol 2001; 420:151-7. [PMID: 11408037 DOI: 10.1016/s0014-2999(01)01016-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Acetylcholine administered to the inside of epithelium-denuded tracheal tubes did cause a potent contraction (2486+/-120 mg). In contrast, a response was hardly observed in tissues with an intact epithelial layer (674+/-81 mg), which was due to both the synthesis of nitric oxide and the activity of acetylcholinesterase, since the contractions to acetylcholine were significantly enhanced after preincubation with N(omega)-nitro-L-arginine methyl ester (L-NAME) or physostigmine (1374+/-65 and 1120+/-65 mg, respectively). In addition, the suppressive effect was caused by the barrier function of the epithelial layer, since preincubation of epithelium-denuded tissues with physostigmine significantly increased the pD2 value for acetylcholine (7.48+/-0.04) compared to intact tissues preincubated with physostigmine (6.32+/-0.10) and epithelium-denuded preparations without physostigmine (6.37+/-0.06). Increasing concentrations of physostigmine administered to the inside of tissues with epithelium did induce a potent spontaneous contraction (1440+/-350 mg) that was prevented by atropine. In contrast to what was expected, the contractile response was diminished in tracheal tubes without epithelium (665+/-221 mg). It is concluded that contractions of epithelium-denuded tissues are more pronounced to exogenous than to endogenous acetylcholine, and that the production and breakdown of this neurotransmitter is very rapid in intact guinea pig airways. Moreover, the release of nitric oxide and the barrier function of the epithelium did suppress the responsiveness to acetylcholine.
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Affiliation(s)
- G Folkerts
- Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, 3508 TB, Utrecht, Netherlands.
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107
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Fedan JS, Van Scott MR, Johnston RA. Pharmacological techniques for the in vitro study of airways. J Pharmacol Toxicol Methods 2001; 45:159-74. [PMID: 11687382 DOI: 10.1016/s1056-8719(01)00154-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- J S Fedan
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505-2888, USA.
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108
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Strohmeier GR, Walsh JH, Klings ES, Farber HW, Cruikshank WW, Center DM, Fenton MJ. Lipopolysaccharide binding protein potentiates airway reactivity in a murine model of allergic asthma. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:2063-70. [PMID: 11160257 DOI: 10.4049/jimmunol.166.3.2063] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development of allergic asthma is influenced by both genetic and environmental factors. Epidemiologic data often show no clear relationship between the levels of allergen and clinical symptoms. Recent data suggest that bacterial LPS may be a risk factor related to asthma severity. Airborne LPS is typically present at levels that are insufficient to activate alveolar macrophages in the absence of the accessory molecule LPS binding protein (LBP). LBP levels are markedly elevated in bronchoalveolar lavage fluids obtained from asthmatic subjects compared with those in normal controls. We hypothesized that LBP present in the lung could augment the pulmonary inflammation and airway reactivity associated with allergic asthma by sensitizing alveolar macrophages to LPS or other bacterial products and triggering them to release proinflammatory mediators. We compared wild-type (WT) and LBP-deficient mice using a defined Ag immunization and aerosol challenge model of allergic asthma. Immunized LBP-deficient mice did not develop substantial Ag-induced airway reactivity, whereas WT mice developed marked bronchoconstriction following aerosol Ag sensitization and challenge with methacholine. Similarly, production of NO synthase 2 protein and the NO catabolite peroxynitrite was dramatically higher in the lungs of WT mice following challenge compared with that in LBP-deficient mice. Thus, NO production appears to correlate with airway reactivity. In contrast, both mice developed similar pulmonary inflammatory cell infiltrates and elevated mucin production. Thus, LBP appears to participate in the development of Ag-induced airway reactivity and peroxynitrite production, but does not seem to be required for the development of pulmonary inflammation.
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Affiliation(s)
- G R Strohmeier
- The Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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109
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Kao YJ, Piedra PA, Larsen GL, Colasurdo GN. Induction and regulation of nitric oxide synthase in airway epithelial cells by respiratory syncytial virus. Am J Respir Crit Care Med 2001; 163:532-9. [PMID: 11179135 DOI: 10.1164/ajrccm.163.2.9912068] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this study, we evaluated the effects of respiratory syncytial virus (RSV) infection on nitric oxide (NO) production in human airway epithelial cells. In addition, we evaluated whether T-helper type 1 (Th1)- and Th2-type cytokines modulate the release of NO in response to RSV infection. To do this, we infected monolayers of A549 cells with RSV and determined nitrite levels in the supernatant fluids. We also measured nitrite levels in human small-airway epithelial cells (SAEC) in primary culture and in the bronchoalveolar lavage fluid (BALF) obtained from Balb/c mice after RSV infection. To further support our observations in these analyses, we performed immunocytochemistry and Western blot analysis for inducible nitric oxide synthase (iNOS) in A549 cells. To evaluate the regulation of NO production in response to RSV, we performed experiments in the absence and presence of the Th1 and Th2 type cytokines: interferon (IFN)-gamma, interleukin (IL)-4, and IL-13. In addition, we assessed the inhibitory effect of dexamethasone on iNOS in RSV infected A549 cells. Results were expressed in terms of nmol/mg protein and shown as percents of control values (mean +/- SE). RSV increased the release of nitrites in A549 cells, SAEC, and BALF. The increase in nitrite levels was supported by immunocytochemistry and Western blot analysis for iNOS protein in A549 cells, indicating activation of iNOS in response to RSV infection. IFN-gamma and IL-13 did not affect the RSV-induced increase in NO production. By contrast, IL-4 and dexamethasone suppressed the release of NO in response to RSV infection. These observations show that RSV infection leads to activation of iNOS within the airway epithelium and that IL-4 and dexamethasone inhibit the production of NO in response to RSV infection.
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Affiliation(s)
- Y J Kao
- Department of Pediatrics, University of Texas-Houston Medical School, Houston 77030, USA
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110
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Takahashi N, Aizawa H, Fukuyama S, Inoue H, Nishima S, Hara N. Thapsigargin, a Ca(2+)-ATPase inhibitor, relaxes guinea pig tracheal smooth muscle by producing epithelium-dependent relaxing factors. Eur J Pharmacol 2000; 410:61-8. [PMID: 11134657 DOI: 10.1016/s0014-2999(00)00840-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A non-phorbol ester-type tumor promoter, thapsigargin has been reported to deplete Ca(2+) stores in endothelial cells by inhibiting Ca(2+)-ATPase, which in turn increases intracellular Ca(2+) by mobilization of extracellular Ca(2+), leading to activation of constitutive nitric oxide synthase (cNOS) and resultant generation of nitric oxide (NO). In the present study, to evaluate the role of Ca(2+) in the release of epithelium-dependent relaxing factor (EpDRF), we determined the effect of thapsigargin (10(-6) M) on the contraction evoked by exogenous Ca(2+) or acetylcholine (10(-5) M) in epithelium-denuded or epithelium-intact smooth muscle from guinea pig trachea. The following results were obtained: (1) In epithelium-denuded smooth muscle, the contraction evoked by exogenous Ca(2+) in Ca(2+)-free solution or by acetylcholine (10(-5) M) in Ca(2+)-containing solution did not change within 20 min after thapsigargin application, but the contraction evoked by exogenous Ca(2+) increased markedly after 120 min, indicating that thapsigargin had no effect on smooth muscle itself within 20 min of application. The following experiments were performed within 20 min of thapsigargin application. (2) In epithelium-intact smooth muscle, thapsigargin significantly suppressed the contraction evoked by acetylcholine, suggesting that thapsigargin stimulate the epithelium to produce EpDRF. N(G)-nitro-L-arginine methylester (L-NAME) partly, but significantly, attenuated this inhibitory effect of thapsigargin. (3) In epithelium-denuded smooth muscle, atropine (10(-6) M) and L-NAME (10(-5) M) did not change the contraction evoked by exogenous Ca(2+) after application of thapsigargin, suggesting that thapsigargin did not stimulate acetylcholine and NO release from nerve terminals. These results suggest that thapsigargin (10(-6) M) may stimulate EpDRF, including NO and other factor(s) by Ca(2+)-dependent mechanisms.
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Affiliation(s)
- N Takahashi
- Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Higashi-ku, Japan
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111
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Man Y, Hart VJ, Ring CJ, Sanjar S, West MR. Loss of epithelial integrity resulting from E-cadherin dysfunction predisposes airway epithelial cells to adenoviral infection. Am J Respir Cell Mol Biol 2000; 23:610-7. [PMID: 11062139 DOI: 10.1165/ajrcmb.23.5.4046] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Epithelial intercellular adhesion is fundamental to the formation of the airway epithelial protective barrier. In this respect, cadherins are important because these adhesion molecules regulate formation and maintenance of epithelial intercellular junctions. To study the importance of airway epithelial integrity in determining susceptibility to virus infection, we used a replication-incompetent adenovirus, RAd35, and an E-cadherin specific function-blocking antibody, SHE78-7, to disrupt intercellular contacts in human bronchial epithelial cell line 16HBE14o- and primary bronchial epithelial cells. After exposure of 16HBE14o- cell cultures to SHE78-7, disruption of the transepithelial permeability barrier was indicated by a loss of transepithelial electrical resistance and an associated increase of mannitol, inulin, and dextran paracellular flux. Subsequent exposure of SHE78-7-treated cell cultures to RAd35 showed a remarkable increase in adenoviral infection as assessed by beta-galactosidase reporter gene expression. In cultures exposed to SHE78-7, disruption of E-cadherin function resulted in infection equivalent to that in control cultures using 16-fold lower viral titers. These studies show that manipulation of E-cadherin function provides a specific means of altering epithelial integrity that in turn determines resistance of airway epithelia to adenoviral infection.
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Affiliation(s)
- Y Man
- Cell Biology Department and Clinical Virology Department, Medicines Research Centre, GlaxoWellcome, Stevenage, United Kingdom.
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112
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Knight DA, Asokananthan N, Watkins DN, Misso NL, Thompson PJ, Stewart GA. Oncostatin M synergises with house dust mite proteases to induce the production of PGE(2) from cultured lung epithelial cells. Br J Pharmacol 2000; 131:465-72. [PMID: 11015296 PMCID: PMC1572366 DOI: 10.1038/sj.bjp.0703612] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The release of PGE(2) and nitric oxide (NO) from the respiratory epithelium may act to dampen inflammation. In other tissues, oncostatin M (OSM), a potent inducer of epithelial antiproteases, has also been shown to interact with IL-1beta to stimulate PGE(2) release. However, whether OSM interacts with pro-inflammatory cytokines and proteases in the production of anti-inflammatory eicosanoids and NO from airway epithelium is unknown. The effect of OSM and the related cytokine leukaemia inhibitory factor (LIF) on PGE(2) and NO production by the respiratory epithelial cell line, A549 in response to pro-inflammatory cytokines as well as protease-rich house dust mite (HDM) fractions and a protease-deficient rye grass pollen extract was examined by immunohistochemistry, cell culture, ELISA and enzyme-immunoassay. Cells treated with a mixture of IL-1beta, IFNgamma and LPS for 48 h produced a 9 fold increase in PGE(2) and a 3 fold increase in NO levels (both P<0.05). Both OSM and LIF were without effect. However, OSM added together with the cytokine mixture synergistically enhanced PGE(2) production (22 fold, P<0.05). OSM also synergistically enhanced PGE(2) production in response to a cysteine protease-enriched, but not serine protease-enriched HDM fraction (P<0.05). Rye grass extract, neither alone nor in combination with OSM, induced PGE(2) or NO production, although it did induce the release of GM-CSF. These observations suggest that OSM is an important co-factor in the release of PGE(2) and NO from respiratory epithelial cells and may play a role in defense against exogenous proteases such as those derived from HDM.
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Affiliation(s)
- D A Knight
- Asthma & Allergy Research Institute, University of Western Australia, Nedlands, Western Australia.
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113
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Toward TJ, Broadley KJ. Airway reactivity, inflammatory cell influx and nitric oxide in guinea-pig airways after lipopolysaccharide inhalation. Br J Pharmacol 2000; 131:271-81. [PMID: 10991920 PMCID: PMC1572332 DOI: 10.1038/sj.bjp.0703589] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2000] [Revised: 04/27/2000] [Accepted: 07/07/2000] [Indexed: 11/08/2022] Open
Abstract
1. The aim of this study was to investigate the relationship between airway reactivity, leukocyte influx and nitric oxide (NO), in conscious guinea-pigs after aerosolized lipopolysaccharide (LPS) exposure. 2. Inhaled histamine (1 mM, 20 s), causing no bronchoconstriction before LPS exposure (30 microg ml(-1), 1 h), caused bronchoconstriction at 0.5 and 1 h (P:<0.02) after LPS exposure. This airway hyperreactivity (AHR) recovered by 2 h. In contrast, 48 h after LPS exposure, the response from a previously bronchoconstrictor dose of histamine (3 mM, 20 s) was attenuated (P:<0.01) i.e. airway hyporeactivity (AHOR). 3. Investigation of the cellular content of bronchoalveolar lavage fluid (BALF) from these animals revealed a rapid (0.5 h: 691 fold increase) and progressive neutrophil influx after LPS exposure (24 h: 36.3+/-2.3x10(6) cells per sample), that subsided 48 h later. Macrophages and eosinophils also time-dependently increased (0.5 h: 4.6+/-0.4 and 0.1+/-0.05; 48 h: 31.0+/-6.0 and 1.8+/-0.3x10(6) cells per sample, respectively) after LPS, compared to vehicle exposure (24 h: neutrophils, eosinophils and macrophages: 0.28+/-0.19, 0.31+/-0.04 and 4.96+/-0. 43x10(6) cells per sample, respectively). 4. The combined NO metabolites in BALF, after vehicle (1 h), or LPS (1 h: AHR and 48 h: AHOR) exposure, were respectively increased (41%, P:<0.01), decreased (47%, P:<0.01) and further increased (80%, P:<0.001), compared with naïve animals. 5. Inhaled N(o)-nitro-L-arginine methyl ester (L-NAME: 1.2 and 12 mM, 15 min), reduced BALF NO metabolites 2 h later, but did not cause AHR to histamine (P:>0.05). When L-NAME inhalation followed LPS, AHR was prolonged from 1 h to at least 4 h (P:<0.01). 6. In summary, aerosolized LPS inhalation caused neutrophil and macrophage airways infiltration, and an early development of AHR followed 48 h later by AHOR to histamine. AHR and AHOR coincided with a respective reduction and elevation in airways NO (metabolites). Thus, NO may aid recovery from AHR, as inhibition of its production prolongs AHR. However, NO deficiency alone is not responsible for LPS-induced AHR.
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Affiliation(s)
- Toby J Toward
- Division of Pharmacology, Welsh School of Pharmacy, Cardiff University, King Edward VII Avenue, Cathays Park, Cardiff, CF10 3XF
| | - Kenneth J Broadley
- Division of Pharmacology, Welsh School of Pharmacy, Cardiff University, King Edward VII Avenue, Cathays Park, Cardiff, CF10 3XF
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114
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Hjoberg J, Folkerts G, van Gessel SB, Högman M, Hedenstierna G, Nijkamp FP. Hyperosmolarity-induced relaxation and prostaglandin release in guinea pig trachea in vitro. Eur J Pharmacol 2000; 398:303-7. [PMID: 10854843 DOI: 10.1016/s0014-2999(00)00289-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In this study, a tracheal perfusion apparatus was used to investigate the nature of the relaxing factor released by hyperosmolarity on the epithelial side of guinea pig trachea. NaCl induced concentration-dependent relaxation. This relaxation was not affected when the trachea was preincubated with a vasoactive intestinal peptide (VIP) receptor antagonist or with the nitric oxide synthesis inhibitor N(G)-monomethyl-L-arginine (L-NMMA). When the prostaglandin synthesis was prevented by preincubation with the phospholipase A(2)-inhibitor quinacrine, or the cyclooxygenase inhibitor indomethacin, the maximal relaxation induced by NaCl was suppressed by 50% (P<0.05). Moreover, the prostaglandin E(2) concentration was four times higher (P<0.05) in the organ bath during the relaxations, whereas the nitric oxide concentration remained unchanged. In conclusion, increased osmolarity on the airway surface leads to the release of prostaglandins, which are involved in part in the hyperosmolarity-induced relaxation of airway smooth muscle. This might be relevant for asthmatic patients since prostaglandin may modulate the bronchoconstrictive response to hyperosmolar stimuli and exercise.
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Affiliation(s)
- J Hjoberg
- Department of Medical Sciences, Clinical Physiology, University Hospital, S-751 85, Uppsala, Sweden.
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115
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Folkerts G, Vlieger JW, de Vries A, Faas S, van Der Linde H, Engels F, de Jong JC, Verheyen FA, Van Heuven-Nolsen D, Nijkamp FP. Virus- and bradykinin-induced airway hyperresponsiveness in guinea pigs. Am J Respir Crit Care Med 2000; 161:1666-71. [PMID: 10806173 DOI: 10.1164/ajrccm.161.5.9710002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The involvement of bradykinin in virus-induced airway hyperresponsiveness (AHR) in guinea pig airways in vivo was determined with the B(2)-receptor antagonist Hoe 140. The efficacy of Hoe 140 treatment was assessed through its effect on the bradykinin-induced (up to 2.5 microgram/100 g B.W. administered intravenously) decrease in blood pressure (BP). Hoe 140 (0.1 micromol/kg), administered subcutaneously twice a day for 5 d almost completely blocked bradykinin-induced changes in BP. Four days after parainfluenza-3 (PI-3) virus infection, guinea pigs showed AHR; excessive airway contraction was found with histamine-receptor stimulation. This hyperresponsiveness was completely inhibited by pretreatment with Hoe 140 (0.1 micromol/kg) administered subcutaneously twice a day for five consecutive days, starting 1 d before virus inoculation. Interestingly, nebulized delivery of bradykinin itself to captopril-treated animals induced an AHR comparable to that observed in virus-treated guinea pigs. Viral infection also caused influx of bronchoalveolar cells into the lungs. Both histologic examinations and lung lavage experiments showed that this cell influx could not be inhibited by pretreatment with Hoe 140. In summary, the results of the study show that bradykinin is involved in a cascade of events leading to AHR after a viral infection in guinea pigs, without affecting bronchoalveolar cell influx.
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Affiliation(s)
- G Folkerts
- Departments of Pharmacology and Pathophysiology, and Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
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116
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Ricciardolo FLM, Trevisani M, Geppetti P, Nadel JA, Amadesi S, Bertrand C. Role of nitric oxide and septide-insensitive NK(1) receptors in bronchoconstriction induced by aerosolised neurokinin A in guinea-pigs. Br J Pharmacol 2000; 129:915-20. [PMID: 10696090 PMCID: PMC1571918 DOI: 10.1038/sj.bjp.0703135] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The tachykinin, neurokinin A (NKA), contracts guinea-pig airways both in vitro and in vivo, preferentially activating smooth muscle NK(2) receptors, although smooth muscle NK(1) receptors may also contribute. In vitro evidence suggests that NKA activates epithelial NK(1) receptors, inducing the release of nitric oxide (NO) and subsequent smooth muscle relaxation. A number of selective NK(1) receptor agonists have been reported to activate both smooth muscle and epithelial NK(1) receptors, however septide appears only to activate smooth muscle NK(1) receptors. The aim of the present study was to investigate whether NKA-induced bronchoconstriction in guinea-pigs in vivo may be limited by NO release via NK(1) receptor activation, and whether selective NK(1) receptor agonists may activate this mechanism differently. Aerosolized NKA caused an increase in total pulmonary resistance (RL) that was markedly reduced by the NK(2) receptor antagonist, SR 48968, and abolished by the combination of SR 48968 and the NK(1) receptor antagonist, CP-99, 994. The increase in RL evoked by NKA was potentiated by pretreatment with the NO synthase (NOs) inhibitor, L-NAME, but not by the inactive enantiomer D-NAME. Potentiation by L-NAME of NKA-induced increase in RL was reversed by L-Arginine, but not by D-Arginine. Pretreatment with L-NAME did not affect the increase in RL induced by the selective NK(2) receptor agonist, [beta-Ala(8)]NKA(4-10), and by the selective NK(1) receptor agonist, septide, whereas it markedly potentiated the increase in RL caused by a different NK(1) selective agonist, [Sar(9),Met(O(2))(11)]SP. Dose-response curves showed that septide was a more potent bronchoconstrictor than [Sar(9),Met(O(2))(11)]SP to cause bronchoconstriction. Pretreatment with the NK(1) receptor antagonist, CP-96,994, abolished the ability of L-NAME to increase bronchoconstriction to aerosolized NKA. Bronchoconstriction to aerosolized NKA was increased by L-NAME, after pretreatment with the NK(3) receptor antagonist, SR 142801. The present study shows that in vivo bronchoconstriction in response to the aerosolized naturally occurring tachykinin, NKA, is limited by its own ability to release relaxant NO via NK(1) receptor activation. This receptor is apparently insensitive to septide, thus justifying, at least in part, the high potency of septide to cause bronchoconstriction in guinea-pigs.
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Affiliation(s)
- Fabio L M Ricciardolo
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, U.S.A
| | - Marcello Trevisani
- Department of Clinical and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Pierangelo Geppetti
- Department of Clinical and Experimental Medicine, University of Ferrara, Ferrara, Italy
- Author for correspondence:
| | - Jay A Nadel
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, U.S.A
| | - Silvia Amadesi
- Department of Clinical and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Claude Bertrand
- Allergy & Inflammation Unit, Roche Bioscience, Palo Alto, California, U.S.A
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117
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Ricciardolo FL, Vergnani L, Wiegand S, Ricci F, Manzoli N, Fischer A, Amadesi S, Fellin R, Geppetti P. Detection of nitric oxide release induced by bradykinin in guinea pig trachea and main bronchi using a porphyrinic microsensor. Am J Respir Cell Mol Biol 2000; 22:97-104. [PMID: 10615071 DOI: 10.1165/ajrcmb.22.1.3706] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Indirect evidence using nitric oxide (NO) synthase (NOS) inhibitors suggests that in guinea-pig airways bradykinin releases bronchoprotective NO. In this study, using a recently developed electrochemical method of NO measurement based on a porphyrinic microsensor, we investigated whether bradykinin releases NO from guinea-pig airways and whether the epithelium is the main source of NO. Further, the Ca(2+)-dependence of bradykinin-induced NO release was assessed stimulating airway preparations with bradykinin in Ca(2+)-free conditions. We also studied the immunohistochemical distribution of the Ca(2+)- dependent constitutive isoforms of NOS (constitutive NOS [cNOS]: neuronal and endothelial [ecNOS]) in our preparations. The porphyrinic microsensor was placed in the bathing fluid onto the mucosal surface of tracheal or main bronchial segments. Addition of bradykinin vehicle (0.9% saline) did not cause any detectable change of the baseline signal. Addition of bradykinin caused an upward shift of the baseline that reached a maximum within 1 to 2 s. The amplitude of the response to bradykinin was concentration-dependent between the range 1 nM to 10 microM, with a maximum effect at 10 microM. Bradykinin-induced NO release was higher in tracheal than in main bronchial segments. The selective bradykinin B(2) receptor antagonist D-Arg(0)-[Hyp(3), Thi(5), D-Tic(7), Oic(8)]bradykinin (1 microM) inhibited NO release induced by a submaximum concentration of bradykinin (1 microM). The ability of bradykinin to release NO was markedly reduced in epithelium-denuded segments, and abolished in Ca(2+)-free conditions and after pretreatment with N(G)-monomethyl-L-arginine (100 microM), but not with N(G)-monomethyl-D-arginine. Both cNOS isoforms were present in trachea and main bronchi, ecNOS being the predominant isoform in the epithelium. The study shows that bradykinin via B(2) receptor activation caused a rapid and Ca(2+)-dependent release of NO, mainly, but not exclusively, derived from the epithelium. It also shows that both cNOS isoforms may be involved in bradykinin-evoked NO release.
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Affiliation(s)
- F L Ricciardolo
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
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118
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Veronesi B, Carter JD, Devlin RB, Simon SA, Oortgiesen M. Neuropeptides and capsaicin stimulate the release of inflammatory cytokines in a human bronchial epithelial cell line. Neuropeptides 1999; 33:447-56. [PMID: 10657523 DOI: 10.1054/npep.1999.0761] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The role of neuropeptides in initiating and modulating airway inflammation was examined in a human bronchial epithelial cell line (i.e. BEAS-2B). At a range of concentrations, exposure of BEAS-2B cells to Substance P (SP) or calcitonin gene related protein resulted in immediate increases in intracellular calcium ([Ca(2+)](i)), the synthesis of the transcripts for the inflammatory cytokines, IL-6, IL-8 and TNFalpha after 2 h exposure, and the release of their proteins after 6 h exposure. Addition of thiorphan (100 nM), an inhibitor of neutral endopeptidase, enhanced the levels of SP-stimulated cytokine release. Stimulation of IL-6 by SP occurred in a conventional receptor-mediated manner as demonstrated by its differential release by fragments SP 4-11 and SP 1-4 and by the blockage of IL-6 release with the non-peptide, NK-1 receptor antagonist, CP-99 994. In addition to the direct stimulation of inflammatory cytokines, SP (0.5 microM), in combination with TNFalpha (25 units/ml), synergistically stimulated IL-6 release. BEAS-2B cells also responded to the botanical irritant, capsaicin (10 microM) with increases in [Ca(2+)](i) and IL-8 cytokine release after 4 h exposure. The IL-8 release was dependent on the presence of extracellular calcium. Capsaicin-stimulated increases of [Ca(2+)](i) and cytokine release could be reduced to control levels by pre-exposure to capsazepine, an antagonist of capsaicin (i.e. vanilloid) receptor(s) or by deletion of extracellular calcium from the exposure media. The present data indicate that the BEAS-2B human epithelial cell line expresses neuropeptide and capsaicin-sensitive pathways, whose activation results in immediate increases of [Ca(2+)](i) stimulation of inflammatory cytokine transcripts and the release of their cytokine proteins.
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Affiliation(s)
- B Veronesi
- National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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119
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Morcillo EJ, Estrela J, Cortijo J. Oxidative stress and pulmonary inflammation: pharmacological intervention with antioxidants. Pharmacol Res 1999; 40:393-404. [PMID: 10527653 DOI: 10.1006/phrs.1999.0549] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reactive oxygen and nitrogen species are generated by several inflammatory and structural cells of the airways. These oxidant species may have important effects on different lung cells as regulators of signal transduction, activators of key transcription factors, and modulators of gene expression and apoptosis. Thus, an increased oxidative stress accompanied by reduced endogenous antioxidant defences may have a role in the pathogenesis of a number of inflammatory pulmonary diseases including asthma. Although antioxidant drugs could play a useful role in the therapy of inflammatory lung diseases, their clinical impact is relatively modest at present. Rigorous clinical investigation with the existing antioxidants and development of new drugs with improved lung bioavailability are necessary in the future.pc 1999 Academic Press@p$hr
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Affiliation(s)
- E J Morcillo
- Department of Pharmacology, Faculty of Medicine and Odontology, University of Valencia, Valencia, Spain
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120
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Dye JA, Madden MC, Richards JH, Lehmann JR, Devlin RB, Costa DL. Ozone effects on airway responsiveness, lung injury, and inflammation. Comparative rat strain and in vivo/in vitro investigations. Inhal Toxicol 1999; 11:1015-40. [PMID: 10562695 DOI: 10.1080/089583799196664] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Asthmatic individuals appear to be particularly sensitive to the effects of certain air pollutants-including ozone (O(3)), an oxidant ambient air pollutant-for reasons that are poorly understood. The general purpose of these studies, therefore, was to expand and improve upon toxicologic methods for assessing ozone-induced effects on the airways of the rat by (1) developing an in vivo testing procedure that allows detection of airway responsiveness changes in rats exposed to ozone; (2) identifying a strain of rat that may be inherently more sensitive to the effects of ozone; and (3) validation of an in vitro epithelial culture system to more directly assess airway cellular/subcellular effects of ozone. Using methacholine inhalation challenges, we detected increased airway responsiveness in senescent F344 rats acutely after ozone exposure (2 ppm x 2 h). We also determined that acutely after ozone exposure (0.5 ppm x 8 h), Wistar rats developed significantly greater lung injury, neutrophilic inflammation, and bronchoalveolar lavage (BAL) fluid concentrations of IL-6 than either Sprague-Dawley (SD) or F344 rats. SD rats had greater BAL fluid concentrations of prostaglandin E(2) (PGE(2)), while F344 rats consistently exhibited the least effect. Wistar rat-derived tracheal epithelial (RTE) cultures were exposed in vitro to air or ozone (0.1-1.0 ppm x 1 h), and examined for analogous effects. In a concentration-dependent manner, ozone exposure resulted in acute but minor cytotoxicity. RT polymerase chain reaction (PCR) analysis of RNA isolated from ozone-exposed cells demonstrated variable increases in steady-state gene expression of IL-6 at 4 h postexposure, while at 24 h cellular fibronectin expression (EIIIA domain) was decreased. Exposure was without effect on macrophage inflammatory protein 2 (MIP-2) or gamma-glutamyl cysteine synthetase expression. At 6 h postexposure, IL-6 synthesis and apical release appeared increased in ozone-exposed cells (1 ppm x 1 h). MIP-2 release was not significantly increased in ozone-exposed cells. At 2 h postexposure, ozone exposure resulted in minor increases in apical fibronectin, but exposure was without effect on basolateral accumulation of fibronectin. Exposure to 1.0, but not 0.1 ppm (x 1 h), increased production of cyclooxygenase (i.e., PGE(2)) and noncyclooxygenase products of arachidonic acid. Results demonstrate that multiple inflammatory mediator pathways are affected by ozone exposure. Such effects could exacerbate morbidity in individuals with preexisting airway inflammation such as asthmatics.
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Affiliation(s)
- J A Dye
- U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, ETD, PTB, MD-82, Research Triangle Park, NC 27711.
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121
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Abstract
It has been suggested that the increased prevalence of atopy and asthma observed in many developed countries over the past 30 y is in part the result of a decrease in the incidence and severity of early childhood infections. The immunologic consequence of this phenomenon has been the expansion of T-lymphocyte populations away from the T-helper 1 (Th1) subset and in the direction of the Th2 subset. This leads to the creation of a cytokine-mediated propensity for the development of an intense inflammatory response in the airways, resulting in oxidative stress, airway tissue injury, and the development of atopy and asthmatic symptomatology. Over this same period, there has been a decreased intake of dietary substances that contribute to antioxidant defense, and this appears to have contributed to the rise of atopy and asthma. Studies evaluating the efficacy of these antioxidant substances in the prevention of asthma and as adjuvants in the treatment of asthma are reviewed, and suggestions are made for the direction of future studies.
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Affiliation(s)
- L S Greene
- Department of Anthropology, University of Massachusetts-Boston 02125-3393, USA.
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122
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Cortijo J, Martí-Cabrera M, de la Asuncíon JG, Pallardó FV, Esteras A, Bruseghini L, Viña J, Morcillo EJ. Contraction of human airways by oxidative stress protection by N-acetylcysteine. Free Radic Biol Med 1999; 27:392-400. [PMID: 10468214 DOI: 10.1016/s0891-5849(99)00070-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We examined the in vitro effects of tert-butylhydroperoxide (tBu-OOH) in human bronchial muscle. tert-Butylhydroperoxide produced concentration-dependent contractions of bronchial rings (maximum effect was 56.5 +/- 9.6% of contraction by 1 mM acetylcholine; effective concentration 50% was approximately 100 microM). tert-Butylhydroperoxide (0.5 mM)-induced contraction was enhanced by epithelial removal but abolished by indomethacin (cyclooxygenase inhibitor) and zileuton (lipoxygenase inhibitor). tert-Butylhydroperoxide produced a transient rise in intracellular calcium in human cultured airway smooth muscle cells (HCASMC). The bronchial reactivity to acetylcholine and histamine was not altered by tBu-OOH. In HCASMC, tBu-OOH (0.5 mM, 30 min) increased malondialdehyde levels (MDA; from 7.80 +/- 0.83 to 26.82 +/- 1.49 nmol mg(-1) protein), accompanied by a decrease of reduced glutathione (GSH; from 16.7 +/- 2.6 to 6.9 +/- 1.9 nmol mg(-1) protein) and an increase of oxidized glutathione (from 0.09 +/- 0.03 to 0.18 +/- 0.03 nmol mg(-1) protein). N-acetylcysteine (0.3 mM) inhibited by approximately 60% the bronchial contraction resulting from tBu-OOH (0.5 mM) and protected cultured cells exposed to tBu-OOH (MDA was lowered to 19.51 +/- 1.19 nmol mg(-1) protein, and GSH content was replenished). In summary, tBu-OOH caused contraction of human bronchial muscle mediated by release of cyclo-oxygenase and lipoxygenase products without producing airways hyperreactivity. N-acetylcysteine decreases tBu-OOH-induced contraction and protects human cultured airway smooth muscle cells exposed to tBu-OOH.
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Affiliation(s)
- J Cortijo
- Department of Pharmacology, Faculty of Medicine and Odontology, University of Valencia, Spain
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123
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Burcin IU, Sahin-Erdemli I, Arzu S, Ilhan M. Impairment of epithelium-dependent relaxation in coaxial bioassay by reactive oxygen species. Eur J Pharmacol 1999; 378:109-14. [PMID: 10478570 DOI: 10.1016/s0014-2999(99)00390-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The purpose of the present study was to investigate the effects of reactive oxygen species on the activity of epithelium-derived relaxant factor (EpDRF) released by guinea-pig tracheal epithelium. Reactive oxygen species were generated by the electrolysis of the physiological buffer in which the tissues were bathed. Epithelium-dependent relaxation induced by acetylcholine in precontracted rat anococcygeus muscle that was placed in epithelium-intact guinea-pig trachea (coaxial bioassay system) was significantly attenuated when the tissues were exposed to electrolysis. Impairment of the acetylcholine response was prevented by incubation with free radical scavengers prior to electrolysis. In isolated rings of guinea-pig trachea, the contractile responses elicited by acetylcholine, histamine and 5-hydroxytryptamine were not altered after electrolysis of the bathing solution. The results of the present study suggested that exposure to reactive oxygen species impaired EpDRF release from guinea-pig trachea epithelium but did not alter the contractility of tracheal smooth muscle.
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Affiliation(s)
- I U Burcin
- Hacettepe University, Faculty of Pharmacy, Department of Pharmacology and Faculty of Medicine, Ankara, Turkey
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124
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Papi A, Amadesi S, Chitano P, Boschetto P, Ciaccia A, Geppetti P, Fabbri LM, Mapp CE. Bronchopulmonary inflammation and airway smooth muscle hyperresponsiveness induced by nitrogen dioxide in guinea pigs. Eur J Pharmacol 1999; 374:241-7. [PMID: 10422765 DOI: 10.1016/s0014-2999(99)00302-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated whether acute exposure to nitrogen dioxide (NO2) causes major inflammatory responses (inflammatory cell recruitment, oedema and smooth muscle hyperresponsiveness) in guinea pig airways. Anaesthetised guinea pigs were exposed to 18 ppm NO2 or air for 4 h through a tracheal cannula. Bronchoalveolar lavage was performed and airway microvascular permeability and in vitro bronchial smooth muscle responsiveness were measured. Exposure to NO2 induced a significant increase in eosinophils and neutrophils in bronchoalveolar lavage fluid, microvascular leakage in the trachea and main bronchi (but not in peripheral airways), and a significant in vitro hyperresponsiveness to acetylcholine, electrical field stimulation, and neurokinin A, but not to histamine. Thus, this study shows that in vivo exposure to high concentrations of NO2 induces major inflammatory responses in guinea pig airways that mimic acute bronchitis induced by exposure to irritant gases in man.
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Affiliation(s)
- A Papi
- Research Centre on Asthma and COPD, Department of Experimental and Clinical Medicine, University of Ferrara, Italy
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125
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126
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Abstract
Airway epithelium: more than just a source for epithelium-derived relaxing factors!
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127
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Turner PJ, Foreman JC. Hyperresponsiveness in the human nasal airway: new targets for the treatment of allergic airway disease. Mediators Inflamm 1999; 8:133-46. [PMID: 10704051 PMCID: PMC1781794 DOI: 10.1080/09629359990469] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Allergic rhinitis is a condition which affects over 15% of the population in the United Kingdom. The pathological process involves two stages: nasal inflammation, and the development of nasal airway hyperresponsiveness (AHR) to allergen and a number of other stimuli. This results in the amplification of any subsequent allergic reaction, contributing to the chronic allergic state. A number of different hypotheses have been proposed to explain the underlying mechanism of AHR, including a role for eosinophil-derived proteins, free radicals and neuropeptides. While there may be a number of independent pathways which can result in AHR, evidence obtained from both animal models and in vivo experiments in humans indicate that some mediators may interact with one another, resulting in AHR. Further research into these interactions may open new avenues for the pharmacological treatment of chronic allergic rhinitis, and possibly other allergic airway diseases.
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Affiliation(s)
- P J Turner
- Department of Pharmacology, University College London, UK
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