endothelin-1 and Asthma

Topics: Animals; Arteriosclerosis; Asthma; Chymases; Endothelin-1; Glomerulonephritis; Humans; Muscle Contraction; Peptide Fragments; Serine Endopeptidases

Endothelin (ET)-1 is an endogenous endothelium-derived peptide, long recognized as a potent vascular smooth muscle spasmogen and mitogen. Strong links have been made between these and other actions of ET-1 and vascular diseases including pulmonary hypertension. Importantly, it is also now established that ET-1 is synthesized in the airway epithelium and that it has a range of effects in the respiratory tract which suggest a significant mediator role in asthma. These actions include airway smooth muscle contraction, bronchoconstriction and proliferation, potentiation of cholinergic neuronal function, mucus hypersecretion of pro-inflammatory activities including the promotion of airway microvascular leakage and oedema. The following is a brief review of the actions of endothelin-1 that suggest a link between endothelin-1 and obstructive airway diseases such as asthma.

Topics: Animals; Asthma; Endothelin-1; Humans; Inflammation Mediators; Lung; Neurotransmitter Agents; Respiratory Tract Diseases

1. There is an increasing amount of research to implicate endothelin (ET)-1, a member of a family of 21 amino acid peptides, as a potentially important mediator in pulmonary diseases, in particular asthma and pulmonary hypertension. Thus, ET-1 fits several of the standard criteria that need to be fulfilled for a pathophysiologically relevant substance. 2. Endothelin-1 is present in abundance in human lung: the major loci for ET-1 are the epithelium, endothelium, endocrine cells and inflammatory cells. Furthermore, the receptors that mediate the biological effects of ET-1, the ETA and ETB receptor subtypes, are found in human lung, predominantly in airway smooth muscle, and vascular smooth muscle and, to a lesser extent, nerves. There is no change in the relative proportions of ETA and ETB receptors in asthmatic versus non-asthmatic bronchial smooth muscle and peripheral lung. 3. Several studies have shown that ET-1 mimics several of the features of asthma (including bronchospasm, airway remodelling, inflammatory cell recruitment and activation, oedema, mucus secretion, airway hyperreactivity and dysfunction in neuronal inputs); however, some other reports are at odds with these findings. 4. Endothelin-1 mimics the two classical features of pulmonary hypertension (pulmonary vascular constriction and remodelling), which is often a serious complication of chronic obstructive pulmonary disease. 5. Intranasal ET-1 produces several of the symptoms of allergic rhinitis. 6. There are several reports of increased levels and/or expression of ET in patients with many pulmonary disorders, in particular asthma or pulmonary hypertension, with some evidence of a correlation between ET amounts and disease severity; however, other studies do not confirm these observations. 7. Despite these intriguing data in support of a pathophysiological role of ET-1 in lung disease, the definitive test and most difficult criteria to fulfil, the clinical evaluation of ET receptor antagonists or ET synthesis inhibitors, has still to be conducted. Only after these pivotal data are available will we be able to determine definitively whether ET-1 is a pathophysiologically important mediator in lung diseases or merely an interesting peptide with several effects in the pulmonary system.

Topics: Asthma; Endothelin Receptor Antagonists; Endothelin-1; Humans; Hypertension, Pulmonary; Lung Diseases; Molecular Mimicry; Receptors, Endothelin

This review seeks to examine the potential contribution of the recently discovered peptide endothelin-1 to the pathophysiology of asthma. The actions of endothelin-1 which mimic features of asthma, the evidence for increased production of endothelin-1 in asthma and the potential for asthma therapy based on modification of the activity of endothelin-1 are reviewed.

Topics: Airway Obstruction; Animals; Asthma; Bronchial Provocation Tests; Endothelin Receptor Antagonists; Endothelin-1; Humans; Inflammation; Mucous Membrane

Bronchial hyperresponsiveness (BHR) is a fundamental characteristic of asthma and has become part of a more recent definition of asthma. Data show a close link between bronchial hyperresponsiveness (both transient and persistent) and airway inflammation. Airway inflammation is orchestrated by a complex network of cytokines. It has been considered that endothelin-1 is involved in bronchoconstriction and airway structural remodelling and has several pro-inflammatory properties of potential relevance to asthma. We focus on endothelin-1, its activities and interaction with other cytokines in the pathogenesis of asthma.

Topics: Airway Resistance; Animals; Asthma; Bronchial Hyperreactivity; Cytokines; Endothelin-1; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Tumor Necrosis Factor-alpha

There is a growing understanding of the effects and potential pathophysiological role of the ETs in asthma and several of the criteria required to strongly implicate ET-1 as a mediator in this disease have been fulfilled. However, some of the information is preliminary, equivocal and requires confirmation. Furthermore, the most important and most difficult criteria, the clinical testing of potent and selective ET receptor antagonists in these diseases has not been conducted and will probably not be completed for several years. A critical area of research continues to be the elucidation and classification of the ET receptor subtypes mediating the diverse effects of ET-1 in the lung. The unequivocal determination of the pathophysiological role of the ETs in asthma awaits the results of clinical trials with appropriate compounds. Only after these results will we know whether ET-1 has fulfilled its promise as a key player in lung pathophysiology, rather than being added to the list of purported important mediators with unfulfilled expectations.

Topics: Asthma; Endothelin-1; Humans; Respiratory System

Omalizumab is a humanized monoclonal anti-IgE antibody, especially useful for the treatment of severe persistent allergic asthma, inadequately controlled despite regular therapy.. The aim of the study was to determine the effect of omalizumab treatment on changes in endothelin-1 (ET-1), which plays an important role in the development of airway inflammation and remodeling in exhaled breath condensate (EBC) in patients with severe asthma.. The study was conducted in a group of 19 patients with severe persistent allergic asthma treated with conventional therapy (according to the Global Initiative for Asthma, 2006) and with or without omalizumab (9 vs. 10 patients). Changes in ET-1 in EBC compared with other inflammatory parameters [exhaled nitric oxide - (FE(NO)), blood eosinophil count, and serum eosinophil cationic protein (ECP)] were measured after 16 and 52 weeks of therapy.. Omalizumab-treated patients demonstrated a statistically significant decrease in the concentrations of ET-1 in EBC, FE(NO), serum ECP, and blood eosinophil count and an increase in spirometry parameters compared to patients with conventional therapy. In the group of omalizumab-treated patients, statistically significant correlations between the decrease in ET-1 in EBC and a decrease in FE(NO), ECP, and blood eosinophil count as well as the increase in forced expiratory volume in 1 s after omalizumab therapy were revealed.. Our results confirmed that anti-IgE therapy with omalizumab in patients with severe persistent allergic asthma results in decreased expression of ET-1 in the airways. This could be very important in limiting airway inflammation and bronchial structural changes caused by such treatment in asthmatic patients.

Topics: Adult; Anti-Asthmatic Agents; Antibodies, Anti-Idiotypic; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Asthma; Breath Tests; Endothelin-1; Female; Humans; Male; Middle Aged; Omalizumab

Endothelin-1 (ET-1) is produced by vascular endothelial cells and epithelial cells, T-lymphocytes and phagocytes. Increased ET-1 levels have been demonstrated in the bronchial epithelium of asthma patients. In vitro, ET-1 stimulates mucus secretion, activates proinflammatory cells - macrophages and mast cells - and serves as a mitogenic stimulus for fibroblasts and smooth muscle. In addition, ET-1 activates phospholipase 2. Compared with healthy individuals, asthma patients have increased ET-1 levels during an attack and following stabilisation. Our study was designed to examine plasma ET-1 (P-ET) levels in paediatric atopic patients newly diagnosed with persistent mild bronchial asthma and 1 month after initiation of montelukast therapy.. Patients' histories were examined, and their blood eosinophil leucocyte count and levels of total serum immunoglobulin E (S-IgE), serum eosinophil cationic protein (S-ECP) and P-ET were determined. Thirty-six patients with persistent mild bronchial asthma were treated with the leukotriene receptor antagonist montelukast, administered once a day for 4 weeks. Second P-ET and S-ECP level determinations were made 4 weeks later with all the children included in the study. P-ET levels were also determined in a group of 27 healthy children who had no atopy in their medical histories and were taking no drugs (including montelukast), and who served as controls.. The mean +/- SD pretreatment P-ET level in the 36 study children was 11.542 +/- 6.408 pg/L, and this decreased to 5.636 +/- 4.419 pg/L after 1 month's therapy with montelukast (statistically significant difference; p < 0.0001). Both of these values were significantly higher (p < 0.0001 and p < 0.031, respectively) than the mean level in the control group of 27 children (3.543 +/- 2.497 pg/L). The mean pretreatment S-ECP level was 35.78 +/- 19.58 microg/L, and this decreased to 19.54 +/- 13.86 microg/L after 1 month's therapy (p < 0.001).. This study demonstrated a decrease in P-ET levels in children with mild asthma receiving montelukast. This indicates a reduction in the severity of the inflammatory response and, hence, provides evidence for the anti-inflammatory effect of montelukast. Monitoring both ET-1 and ECP levels at regular follow-up may be useful in assessing these two facets of activity of chronic inflammation in bronchial asthma.

Topics: Acetates; Administration, Intranasal; Adolescent; Albuterol; Anti-Asthmatic Agents; Asthma; Bronchodilator Agents; Child; Cyclopropanes; Drug Administration Schedule; Endothelin-1; Eosinophil Cationic Protein; Female; Humans; Leukotriene Antagonists; Male; Quinolines; Severity of Illness Index; Sulfides; Time Factors

To characterize asthma symptoms and pulmonary function throughout two menstrual cycles, with and without exogenous estradiol administration, in women with premenstrual asthma, and to determine the effect of estradiol administration on asthma symptoms, pulmonary function, quality of life, and biomarkers of airway inflammation.. Double-blind, randomized, placebo-controlled, crossover study.. Respiratory clinic and clinical research center.. Twelve women with documented premenstrual asthma (> or = 20% premenstrual worsening of asthma symptoms and/or of peak expiratory flow [PEF] during a 1-month screening phase).. Each woman received either estradiol 2 mg or placebo orally between cycle days 23 and 28 (i.e., premenstrually, or before the onset of menses) in the first cycle and then crossed over to the other arm in the second cycle. Throughout both cycles, the women recorded daily morning and evening PEF readings and asthma symptoms.. Spirometry testing and measurement of serum estradiol and biomarkers of airway inflammation were performed on days 8 (follicular phase), 22 (luteal phase), and 28 (premenstrually) of both the estradiol and placebo cycles. During the two premenstrual visits, the Asthma Quality of Life Questionnaire was administered. No notable differences were observed between the estradiol and placebo cycles in daily PEF recordings or composite asthma symptoms scores. The area under the curve (AUC) for the composite asthma symptoms versus time profile was numerically, but not statistically, lower (denoting less severe symptoms) during the estradiol cycle than during the placebo cycle. Likewise, no significant difference in AUC values for morning PEF or evening PEF was found between the estradiol cycle and the placebo cycle. Despite differences (p<0.05) in day-28 estradiol concentrations for estradiol and placebo cycles, no significant differences were found in forced expiratory volume in 1 second, serum endothelin-1, serum and urine eosinophil protein X, urine leukotriene E4, or quality-of-life scores.. Exogenously administered estradiol did not have a significant effect in women with premenstrual asthma whose asthma was classified predominantly as mild and under excellent control. As in the case of premenstrual syndrome, the placebo effect may be prominent in premenstrual asthma. Further trials, involving women with more severe asthma under poorer control, are warranted to discern underlying mechanisms for the worsening of asthma in relation to menstruation.

Topics: Adult; Anti-Inflammatory Agents; Antioxidants; Asthma; Biomarkers; Creatinine; Cross-Over Studies; Double-Blind Method; Endothelin-1; Eosinophil-Derived Neurotoxin; Estradiol; Female; Humans; Leukotriene E4; Menstrual Cycle; Progesterone; Quality of Life; Ribonucleases

To observe the therapeutic effect of Yiqi Bushen Huoxue herbs (YQBSHX, the Chinese herbs for supplementing Qi, replenishing Kidney and activating blood circulation) on children asthma in regard to its effect on the serum levels of nitric oxide (NO), endothelin-1 (ET-1) and circulating endothelial cells (CEC).. Two hundred children with asthma were divided into two groups, the YQBSHX and the control group, and their serum levels of NO, ET-1 and CEC were detected in acute and remission stage respectively. Twenty cases in each group were followed-up for 1 year to observe the frequency of asthma attack and the changes in ET-1, NO and CEC levels.. Serum levels of ET-1, NO and CEC in patients of acute stage were obviously raised. After treatment, the above-mentioned criteria in the YQBSHX group were significantly lower than those in the control group (P < 0.01). And the frequency of attack in the YQBSHX group was markedly reduced.. YQBSHX herbs could reduce ET-1, NO and CEC levels in children asthma, lessen the frequency of attack, therefore, to elevate the cure rate of children asthma.

Topics: Asthma; Child; Child, Preschool; Drugs, Chinese Herbal; Endothelin-1; Female; Follow-Up Studies; Humans; Infant; Male; Nitric Oxide; Phytotherapy

Endothelin (ET)-1 is a potent bronchoconstrictor, and asthmatics demonstrate bronchial hyperresponsiveness to ET-1 given by inhalation. Angiotensin II (Ang II) is increased in plasma in acute severe asthma, causes bronchoconstriction in asthmatics, and potentiates contractions induced by ET-1 in bovine bronchial smooth muscle in vitro, and contractions induced by methacholine both in vitro and in vivo. We wished to examine any potentiation of the bronchoconstrictor activity of inhaled ET-1 by infused Ang II at subbronchoconstrictor doses.. Double-blind randomized placebo-controlled study.. Asthma research unit in university hospital.. Eight asthmatic subjects with baseline FEV1 88% predicted, bronchial hyperreactivity (geometric mean, concentration of methacholine producing 20% fall, methacholine PC20 2.5 mg/mL), and mean age 37.1 years.. We examined the effect of subbronchoconstrictor doses of infused Ang II (1 ng/kg/min and 2 ng/kg/min) or placebo on bronchoconstrictor responses to inhaled ET-1 (dose range, 0.96 to 15.36 nmol).. Oxygen saturation, noninvasive BP, and spirometric measurements were made throughout the study visits. Blood was sampled for plasma Ang II levels at baseline and before and after ET-1 inhalation.. Ang II infusion did not produce bronchoconstriction per se at either dose prior to ET-1 challenge. Bronchial challenge with inhaled ET-1 produced dose-dependent bronchoconstriction, but there was no difference in bronchial responsiveness to ET-1 comparing infusion of placebo with Ang II at 1 ng/kg/min or 2 ng/kg/min (geometric mean, concentration of ET-1 producing 15% fall, 5.34 nmol, 4.95 nmol, and 4.96 nmol, respectively) (analysis of variance, p > 0.05). There was an increase in systolic and diastolic BP at the higher dose of Ang II compared to placebo (mean 136/86 vs 117/75 mm Hg, respectively). Plasma Ang II was elevated following infusion of both doses of Ang II compared to placebo.. In contrast to the potentiating effect on methacholine-induced bronchoconstriction, Ang II at subbronchoconstrictor doses does not potentiate ET-1-induced bronchoconstriction in asthma.

Topics: Adult; Angiotensin II; Asthma; Blood Pressure; Bronchial Hyperreactivity; Bronchoconstriction; Double-Blind Method; Drug Synergism; Endothelin-1; Female; Humans; Male; Middle Aged

Endothelin-1 (ET-1) is an effective vasoconstrictor and has bronchoconstricting property. Recent findings in vivo and in vitro indicate the influence of ET-1 on bronchial smooth muscle tone. ET-1 concentration was detected in BAL-Fluid in patients with bronchial asthma. Previous studies indicated an increase in ET-1 serum concentrations in the course of exacerbation of asthma. The purpose of our study was to compare ET-1 concentrations in sera of asthmatics during the asymptomatic period and after metacholine provocation. The study was performed in a group of 16 patients with mild bronchial asthma and in 11 healthy subjects. ET-1 concentrations in sera were evaluated by Elisa method (kit R&D USA). Bronchial provocation with metacholine was performed in asthmatics using Bronchoscreen. The result was considered as positive with FEV1, decrease of at least 20%. Airway responsiveness to metacholine was expressed as PC20. The results were analyzed statistically by means of the Student's test. The baseline ET-1 levels in sera of healthy donors were lower then in asthmatics group (x1' = 4.72 +/- 1.01, x1 = 11.53 +/- 3.68 pg/ml, p < 0.001). We found a statistically significant increase of ET1-1 concentration in sera after inhalation of metacholine (x1 = 11.55 +/- 3.68; x2 = 24.08 +/- 4.09 pg/ml, p < 0.001). The results indicate that ET-1 may play a role in bronchospasm in asthmatics.

Topics: Adult; Asthma; Bronchi; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Endothelin-1; Humans; Methacholine Chloride; Muscle, Smooth

Endothelin (ET)-1 is a 21-amino acid peptide which has potent bronchoconstrictor activity. Animal studies show elevation of ET-1 during experimental airway inflammation, and inhibition of inflammation by endothelin-antagonists, suggesting pro-inflammatory activity for ET-1.. We wanted to assess any acute influence that bronchoconstrictor doses of inhaled ET-1 might have on cells, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, nitrite (NO2) and albumin in induced sputum in asthma.. Bronchial challenge was performed using nebulized ET-1 (nebulized dose range 0.96-15.36 nmol) and placebo in 10 adult asthmatic subjects in a randomized double-blind placebo-controlled cross-over study. Sputum induction was performed 30 min and 4 h after placebo or ET-1 bronchial challenge.. All subjects experienced dose-dependent bronchoconstriction to inhaled ET-1 with a mean (range) PC15 forced expiratory volume in 1 s (FEV1) to ET-1 of 9.45 (1.2-21.7) nmol. Comparing ET-1 with placebo inhalation, there was no change in sputum differential cell counts, TNFalpha, IL-1beta, NO2 or albumin at 30 min or 4 h after inhalation, nor was there a difference in these parameters at 4 h compared with 30 min after ET-1 inhalation. There was no fall in FEV1 at 4 h after ET-1 inhalation, suggesting that ET-1 inhalation is not associated with a late bronchoconstrictor response.. We conclude that inhaled ET-1 does not appear to stimulate an acute inflammatory response in asthma as assessed by differential cell count, TNFalpha, IL-1beta, NO2 and albumin concentrations in induced sputum.

Topics: Adult; Albumins; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Cell Count; Cross-Over Studies; Cytokines; Double-Blind Method; Endothelin-1; Female; Humans; Interleukin-1; Male; Methacholine Chloride; Middle Aged; Nitric Oxide; Sputum; Tumor Necrosis Factor-alpha

Endothelin-1 (ET-1) has been indirectly implicated in the pathophysiology of asthma, and it is a potent bronchoconstrictor both in vitro and by inhalation in animal models in vivo. We examined the effect of inhaled ET-1 on airway tone in comparison with methacholine in eight asthmatics and five healthy volunteers in a double-blind randomized fashion. After a screening methacholine challenge each asthmatic had two ET-1 (doubling dose range, 0.96 to 15.36 nmol) and one methacholine (doubling dose range, 0.33 to 21.0 mumol) challenge, and normal subjects had a single ET-1 challenge. Inhalations were delivered using a dosimeter, and lung function measurements were made using constant-volume body plethysmography, with end points being a 35% fall in specific airway conductance (SGaw) and a 15% fall in FEV1. Samples for plasma ET-1 were taken before and after the inhalations, and pulse, blood pressure and oxygen saturation were monitored throughout the inhalations. All the asthmatic subjects displayed rapid-onset (< 5 min) dose-dependent bronchoconstriction to ET-1 across the dose range used, with mean (range) ET-1 PC35SGaw values of 5.15 (1.4 to 13.9) nmol, and 4.3 (1.2 to 8.3) nmol for the two ET-1 inhalations, and 0.42 (0.2 to 0.7) mumol for methacholine. Albuterol completely and rapidly reversed ET-1-induced bronchoconstriction, and in two patients not given albuterol, bronchoconstriction lasted 60 to 90 min. No significant bronchoconstriction was observed in any of the healthy volunteers across the ET-1 dose range used (mean PC35SGaw > 15.36 nmol). Oxygen saturation did not alter in either group, and plasma ET-1 did not change after ET-1 inhalation. Noninvasive blood pressure measurements revealed a fall in systolic blood pressure in normal subjects, with no change in asthmatics. Endothelin-1 is a potent bronchoconstrictor in asthma, with a bronchoconstrictor potency around 100 times that of methacholine in asthma. Asthmatics exhibit bronchial hyperreactivity to ET-1, and inhaled ET-1 can safely be given to asthmatics and normal subjects in the nebulized dose range 0.96 to 15.36 nmol.

Topics: Adult; Aerosols; Asthma; Bronchoconstriction; Bronchoconstrictor Agents; Double-Blind Method; Endothelin-1; Female; Humans; Male; Methacholine Chloride; Middle Aged; Respiratory Function Tests; Single-Blind Method; Statistics, Nonparametric; Time Factors

Endothelin-I (ET-I) levels in BALF of symptomatic (n = 7) and asymptomatic (n = 10) asthmatic patients, sarcoidosis (n = 10), allergic alveolitis (n = 6) and healthy volunteers (n = 6) was evaluated. In all patients BALF level of endothelin-I was assessed by radioimmunoassay. We observed that patients with symptomatic asthma had more increased amounts of ET-I in BALF in comparison with asymptomatic asthmatics, patients with sarcoidosis, allergic alveolitis and control group.. 1. Presence of ET-I in BALF indicates that this peptide is involved in the pathogenesis of bronchial asthma, sarcoidosis and allergic alveolitis. 2. Endothelin-I is involved in bronchial smooth muscle contraction.

Topics: Adult; Alveolitis, Extrinsic Allergic; Asthma; Bronchoalveolar Lavage Fluid; Endothelin-1; Female; Humans; Male; Middle Aged; Respiratory Tract Diseases; Sarcoidosis, Pulmonary

The renin-angiotensin system is activated in acute severe asthma. The precise mechanism of activation is at present unknown, but may involve, beta2-agonists, catecholamines or proteases released in airway inflammation. This study aims to identify potential factors involved in the activation of the renin-angiotensin system in acute asthma. Forty asthmatics with severe exacerbations of asthma, assessed by measurement of peak expiratory flow rate (mean (SD) 35 (18)% predicted), oxygen saturation (94 (4)%) and pulse rate (108 (16) beats x min(-1)) were recruited. Nineteen (48%) asthmatics had elevated plasma angiotensin II levels (median (interquartile range) 10.9 (4.3-23.5) pg x mL(-1) (normal range 3-12 pg x mL(-1))) and 10 (25%) had elevated plasma renin concentration (22.0 (10.0-50.0) microU x mL(-1) (normal range 9-50 microU x mL(-1))). Plasma renin and angiotensin II correlated strongly, implying renin-dependent angiotensin II formation. No correlation was found between plasma salbutamol, adrenaline, nor-adrenaline, endothelin-1, histamine, eosinophilic cationic protein, serum angio-tensin-converting enzyme (ACE) activity, total immunoglobulin E (IgE), urea and electrolytes, indicators of the severity of the attack, atopic status, blood pressure and renin or angiotensin II levels. We conclude that although a subpopulation of asthmatics appear to have raised renin and angiotensin II during attacks of acute, severe asthma, the mechanism of activation of the renin-angiotensin system remains unclear.

Topics: Acute Disease; Adolescent; Adult; Angiotensin II; Asthma; Catecholamines; Endothelin-1; Female; Forced Expiratory Volume; Heart Rate; Humans; Male; Middle Aged; Oxygen Consumption; Peak Expiratory Flow Rate; Peptidyl-Dipeptidase A; Renin; Renin-Angiotensin System; Sensitivity and Specificity; Severity of Illness Index

Reduction of histone deacetylase (HDAC) 2 expression and activity may contribute to amplified inflammation in patients with severe asthma. Connective tissue growth factor (CTGF) is a key mediator of airway fibrosis in severe asthma. However, the role of the HDAC2/Sin3A/methyl-CpG-binding protein (MeCP) 2 corepressor complex in the regulation of CTGF expression in lung fibroblasts remains unclear.. The role of the HDAC2/Sin3A/MeCP2 corepressor complex in endothelin (ET)-1-stimulated CTGF production in human lung fibroblasts (WI-38) was investigated. We also evaluated the expression of HDAC2, Sin3A and MeCP2 in the lung of ovalbumin-induced airway fibrosis model.. HDAC2 suppressed ET-1-induced CTGF expression in WI-38 cells. ET-1 treatment reduced HDAC2 activity and increased H3 acetylation in a time-dependent manner. Furthermore, overexpression of HDAC2 inhibited ET-1-induced H3 acetylation. Inhibition of c-Jun N-terminal kinase, extracellular signal-regulated kinase, or p38 attenuated ET-1-induced H3 acetylation by suppressing HDAC2 phosphorylation and reducing HDAC2 activity. Overexpression of both Sin3A and MeCP2 attenuated ET-1-induced CTGF expression and H3 acetylation. ET-1 induced the disruption of the HDAC2/Sin3A/MeCP2 corepressor complex and then prompted the dissociation of HDAC2, Sin3A, and MeCP2 from the CTGF promoter region. Overexpression of HDAC2, Sin3A, or MeCP2 attenuated ET-1-stimulated AP-1-luciferase activity. Moreover, Sin3A- or MeCP2-suppressed ET-1-induced H3 acetylation and AP-1-luciferase activity were reversed by transfection of HDAC2 siRNA. In an ovalbumin-induced airway fibrosis model, the protein levels of HDAC2 and Sin3A were lower than in the control group; however, no significant difference in MeCP2 expression was observed. The ratio of phospho-HDAC2/HDAC2 and H3 acetylation in the lung tissue were higher in this model than in the control group. Overall, without stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex inhibits CTGF expression by regulating H3 deacetylation in the CTGF promoter region in human lung fibroblasts. With ET-1 stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex is disrupted and dissociated from the CTGF promoter region; this is followed by AP-1 activation and the eventual initiation of CTGF production.. The HDAC2/Sin3A/MeCP2 corepressor complex is an endogenous inhibitor of CTGF in lung fibroblasts. Additionally, HDAC2 and Sin3A may be of greater importance than MeCP2 in the pathogenesis of airway fibrosis.

Topics: Asthma; Co-Repressor Proteins; Connective Tissue Growth Factor; Endothelin-1; Fibroblasts; Histone Deacetylase 2; Humans; Luciferases; Lung; Ovalbumin; Pulmonary Fibrosis; Transcription Factor AP-1

Rhinovirus (RV) infection of airway epithelial cells triggers asthma exacerbations, during which airway smooth muscle (ASM) excessively contracts. Due to ASM contraction, airway epithelial cells become mechanically compressed. We previously reported that compressed human bronchial epithelial (HBE) cells are a source of endothelin-1 (ET-1) that causes ASM contraction. Here, we hypothesized that epithelial sensing of RV by TLR3 and epithelial compression induce ET-1 secretion through a TGF-β receptor (TGFβR)-dependent mechanism.. To test this, we used primary HBE cells well-differentiated in air-liquid interface culture and two mouse models (ovalbumin and house dust mite) of allergic airway disease (AAD). HBE cells were infected with RV-A16, treated with a TLR3 agonist (poly(I:C)), or exposed to compression. Thereafter, EDN1 (ET-1 protein-encoding gene) mRNA expression and secreted ET-1 protein were measured. We examined the role of TGFβR in ET-1 secretion using either a pharmacologic inhibitor of TGFβR or recombinant TGF-β1 protein. In the AAD mouse models, allergen-sensitized and allergen-challenged mice were subsequently infected with RV. We then measured ET-1 in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness (AHR) following methacholine challenge.. Our data reveal that RV infection induced EDN1 expression and ET-1 secretion in HBE cells, potentially mediated by TLR3. TGFβR activation was partially required for ET-1 secretion, which was induced by RV, poly(I:C), or compression. TGFβR activation alone was sufficient to increase ET-1 secretion. In AAD mouse models, RV induced ET-1 secretion in BALF, which positively correlated with AHR.. Our data provide evidence that RV infection increased epithelial-cell ET-1 secretion through a TGFβR-dependent mechanism, which contributes to bronchoconstriction during RV-induced asthma exacerbations.

Topics: Animals; Asthma; Endothelin-1; Humans; Hypersensitivity; Mice; Receptors, Transforming Growth Factor beta; Rhinovirus; Toll-Like Receptor 3

Icariin (ICA) is the major active ingredient extracted from Chinese herbal medicine Epimedium, which has the effects of improving cardiovascular function, inducing tumor cell differentiation and increasing bone formation. It is still rarely reported that ICA can exert its therapeutic potential in asthma via anti-airway remodeling. The point of the study was to estimate the role of ICA in anti-. airway remodeling and its possible mechanism of action in a mouse ovalbumin. (OVA)-induced asthma model.. Hematoxylin and Eosin Staining were performed for measuring airway remodeling related indicators. ELISA, Western blot and Immunohistochemistr-. y (IHC) were used for analyzing the level of protein. RT-PCR was used for analyzing the level of mRNA.. On days 1 and 8, mice were sensitized to OVA by intraperitoneal injection. From day 16 to day 43, previously sensitized mice were exposed to OVA once daily by nebulizer. Interventions were performed orally with ICA (ICA low, medium and high dose groups) or dexamethasone 1 h prior to each OVA exposure. ICA improves pulmonary function, attenuates pulmonary inflammation and airway remodeling in mice exposed to OVA. Histological and Western blot analysis of the lungs show that ICA suppressed transforming growth factor beta 1 and vascular endothelial growth factor expression. Increase in interleukin 13 and endothelin-1 in serum and bronchoalveolar lavage fluid in OVA-induced asthmatic mice are also decreased by ICA. ICA attenuates airway smooth muscle cell proliferation, as well as key factors in the MAPK/Erk pathway.. The fact that ICA can alleviate OVA-induced asthma at least partly through inhibition of ASMC proliferation via MAPK/Erk pathway provides a solid theoretical basis for ICA as a replacement therapy for asthma. These data reveal the underlying reasons of the use of ICA-rich herbs in Traditional Chinese Medicine to achieve good results in treating asthma.

Topics: Airway Remodeling; Animals; Asthma; Drugs, Chinese Herbal; Endothelin-1; Epimedium; Female; Flavonoids; Humans; Interleukin-13; Mice; Mice, Inbred BALB C; Vascular Endothelial Growth Factor A

Asthma is a chronic inflammatory condition of the airways and patients sensitized to airborne fungi such as Aspergillus fumigatus have more severe asthma. Thickening of the bronchial subepithelial layer is a contributing factor to asthma severity for which no current treatment exists. Airway epithelium acts as an initial defence barrier to inhaled spores, orchestrating an inflammatory response and contributing to subepithelial fibrosis.. We aimed to analyse the production of pro-fibrogenic factors by airway epithelium in response to A fumigatus, in order to propose novel anti-fibrotic strategies for fungal-induced asthma.. We assessed the induction of key pro-fibrogenic factors, TGF-β1, TGF-β2, periostin and endothelin-1, by human airway epithelial cells and in mice exposed to A fumigatus spores or secreted fungal factors.. Aspergillus fumigatus specifically caused production of endothelin-1 by epithelial cells in vitro but not any of the other pro-fibrogenic factors assessed. A fumigatus also induced endothelin-1 in murine lungs, associated with extensive inflammation and airway remodelling. Using a selective endothelin-1 receptor antagonist, we demonstrated for the first time that endothelin-1 drives many features of airway remodelling and inflammation elicited by A fumigatus.. Our findings are consistent with the hypothesis that elevated endothelin-1 levels contribute to subepithelial thickening and highlight this factor as a possible therapeutic target for difficult-to-treat fungal-induced asthma.

Topics: Airway Remodeling; Animals; Aspergillosis; Aspergillus fumigatus; Asthma; Endothelin-1; Humans; Male; Mice; Respiratory Mucosa

During acute bronchoconstriction, the airway epithelium becomes mechanically compressed, as airway smooth muscle contracts and the airway narrows. This mechanical compression activates airway epithelium to promote asthmatic airway remodeling. However, whether compressed airway epithelium can feed back on the cause of bronchoconstriction has remained an open question. Here we examine the potential for epithelial compression to augment proliferation and contraction of airway smooth muscle, and thus potentiate further bronchoconstriction and epithelial compression. Well-differentiated primary human bronchial epithelial (HBE) cells maintained in air-liquid interface culture were mechanically compressed to mimic the effect of bronchoconstriction. Primary human airway smooth muscle (HASM) cells were incubated with conditioned media collected from mechanically compressed HBE cells to examine the effect of epithelial-derived mediators on HASM cell proliferation using an EdU assay and HASM cell contraction using traction microscopy. An endothelin receptor antagonist, PD-145065, was employed to probe the role of HBE cell-derived endothelin-1 on the proliferation and contraction of HASM cells. Conditioned media from compressed HBE cells increased HASM cell proliferation, independent of the endothelin-1 signaling pathway. However, conditioned media from compressed HBE cells significantly increased HASM cell basal contraction and histamine-induced contraction, both of which depended on the endothelin-1 signaling pathway. Our data demonstrate that mechanical compression of bronchial epithelial cells contributes to proliferation and basal contraction of airway smooth muscle cells and that augmented contraction depends on epithelial cell-derived endothelin-1. By means of both airway smooth muscle remodeling and contractility, our findings suggest a causal role of epithelial compression on asthma pathogenesis.

Topics: Airway Remodeling; Asthma; Bronchoconstriction; Cell Proliferation; Cells, Cultured; Endothelin-1; Humans; Muscle Contraction; Muscle, Smooth; Respiratory System; Signal Transduction

To study the anti-asthmatic effects of butylphthalide in guinea pig.. Butylphthalide at the concentrations of 1、10、100 mg/L had an-ti-spasmodic effects on spasmodical tracheal smooth muscle of guinea pig (15.08 ±7.68、42.41 ±13.54、77.56 ±24.82 to acetylcholine, 19.40 ±7.60、56.84 ±11.72、76.35 ±19.40 to histamine), which showed a certain dose-effect relationship. Butylphthalide could prolong asth-matic incubation period (53.3 ±13.2、33.1 ±13.0), improve asthmatic behaviors, reduce NO in serum (78.71 ±19.40、84.75 ±20.97) and ET-1 in bronchoalveolar lavage fluid (24.30 ±5.80、28.50 ±6.31) (. Butylphthalide has some effects of anti-asthma and one of the mechanisms is to relieve abnormal increase of NO and ET-1.

Topics: Animals; Anti-Asthmatic Agents; Asthma; Benzofurans; Endothelin-1; Guinea Pigs; Muscle, Smooth; Nitric Oxide; Trachea

To study the effects of butylphthalide on bronchial asthma in guinea pigs, and investigate the involvement of endothelin.. In guinea pigs, bronchial asthma was induced by injection of ovalbumin (OVA) and provoked by inhalation of OVA, and the effects of butylphthalide on asthma were evaluated through the changes it induced by OVA, pulmonary function, endothelin-1 (ET-1) contents and activity of endothelin converting enzyme-1 (ECE-1) in bronchoalveolar lavage fluid (BALF), serum and lung tissue, and the gene expression of ET-1 in lung tissue.. Butylphthalide significantly improved pulmonary function, lowered asthmatic behavior score, inhibited the activity of ECE-1, and reduced ET-1 gene expression level in lung tissue.. Butylphthalide has an anti-asthma effect and the mechanisms involve inhibition of ECE-1 activity and lowering of ET-1geng expression.

Topics: Animals; Asthma; Benzofurans; Bronchoalveolar Lavage Fluid; Endothelin-1; Guinea Pigs; Ovalbumin

The elevated level of endothelin-1 (ET-1) has been detected in the bronchoalveolar lavage of patients with severe asthma, acute lung injury, acute respiratory distress syndrome, and sepsis. ET-1 may affect vessel tone together with lung physiology and pathology. Vascular cell adhesion molecule-1 (VCAM-1) is one kind of adhesion molecules participating in the process of polymorphonuclear leukocyte transmigration and regulating the occurrence and amplification of tissue inflammation. However, the molecular mechanisms underlying ET-1-mediated expression of VCAM-1 on human tracheal smooth muscle cells (HTSMCs) were largely unknown. Here we reported that ET-1 stimulated expression of VCAM-1 gene on HTSMCs, which was blocked by pretreatment with the inhibitors of ET receptors, Src, matrix metalloproteinases (MMPs), epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), phosphatidylinositol 3-kinase (PI3K), AKT, MEK1/2, and p300, suggesting the participation of these signaling components in ET-1-regulated HTSMC responses. Furthermore, transfection with small-interfering RNA (siRNA) of Src, AKT, p42 mitogen-activated protein kinase (MAPK), or p300 downregulated the respective proteins and significantly attenuated ET-1-induced VCAM-1 expression. ET-1 also stimulated phosphorylation of Src, EGFR, PDGFR, AKT, p42/p44 MAPK, and Elk-1 and acetylation of histone H4 on HTSMCs. Immunoprecipitation assay showed the association between Elk-1 and p300 in the nucleus. Adhesion assay revealed that the adhesion of THP-1 to HTSMCs challenged with ET-1 was increased, which was attenuated by the inhibitors of ET receptors, Src, MMPs, EGFR, PDGFR, PI3K, AKT, p42/p44 MAPK, and p300. Taken together, these data suggested that ET-1 promotes occurrence and amplification of pathology-related airway inflammation via enhancing VCAM-1 expression in an ET receptor/Src/MMP/EGFR, PDGFR/PI3K/AKT/p42/p44 MAPK/Elk-1/p300 pathway in HTSMCs.

Topics: Acetylation; Asthma; Cells, Cultured; Endothelin-1; ets-Domain Protein Elk-1; Gene Expression; Humans; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinase 1; Myocytes, Smooth Muscle; p300-CBP Transcription Factors; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-akt; Receptors, G-Protein-Coupled; Trachea; Transcriptional Activation; Vascular Cell Adhesion Molecule-1

Current asthma therapy may not adequately target contraction of smaller intrapulmonary airways, which are a major site of airway obstruction and inflammation. The aim of this study was to characterise responses of mouse intrapulmonary airways to prostaglandin E(2) (PGE(2)) and compare its dilator efficacy with the β(2)-adrenoceptor agonist salbutamol in situ, using lung slices.. Lung slices (150 μm) were prepared from male Balb/C mice. Changes in intrapulmonary airway lumen area were recorded and analysed by phase-contrast microscopy. Relaxation to PGE(2) and salbutamol were assessed following various levels of pre-contraction with methacholine, serotonin or endothelin-1, as well as following overnight incubation with PGE(2) or salbutamol. The mechanism of PGE(2)-mediated relaxation was explored using selective EP antagonists (EP(1/2) AH6809; EP(4) L-161982) and Ca(2+)-permeabilized slices, where airway responses are due to regulation of Ca(2+)-sensitivity alone.. PGE2 elicited EP(1/2)-mediated relaxation of intrapulmonary airways. PGE(2) was more potent than salbutamol in opposing submaximal pre-contraction to all constrictors tested, and only PGE(2) opposed maximal pre-contraction with endothelin-1. Relaxation to PGE(2) was maintained when contraction to methacholine was mediated via increased Ca(2+)-sensitivity alone. PGE(2) was less sensitive to homologous or heterologous desensitization of its receptors than salbutamol.. The greater efficacy and potency of PGE(2) compared to salbutamol in mouse intrapulmonary airways supports further investigation of the mechanisms underlying this improved dilator responsiveness for the treatment of severe asthma.

Topics: Adrenergic beta-2 Receptor Agonists; Albuterol; Animals; Asthma; Bronchodilator Agents; Calcium; Dinoprostone; Endothelin-1; Lung; Male; Methacholine Chloride; Mice; Mice, Inbred BALB C; Serotonin

Epidemiological studies have revealed that intrauterine growth retardation (IUGR) or low birth weight is linked to the later development of asthma. Epigenetic regulatory mechanisms play an important role in the fetal origins of adult disease. However, little is known regarding the correlation between epigenetic regulation and the development of asthma following IUGR.. An IUGR and ovalbumin (OVA)-sensitization/challenge rat model was used to study whether epigenetic mechanisms play a role in the development of asthma following IUGR.. Maternal nutrient restriction increased histone acetylation levels of the endothelin-1 (ET-1) gene promoter in lung tissue of offspring, but did not cause significant alterations of DNA methylation. The effect was maintained until 10 weeks after birth. Furthermore, these epigenetic changes may have induced IUGR individuals to be highly sensitive to OVA challenge later in life, resulting in more significant changes related to asthma.. These findings suggest that epigenetic mechanisms might be closely associated with the development of asthma following IUGR, providing further insight for improved prevention of asthma induced by environmental factors.

Topics: Acetylation; Age Factors; Allergens; Animals; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; DNA Methylation; Endothelin-1; Epigenesis, Genetic; Female; Fetal Growth Retardation; Gene Expression Regulation; Genetic Predisposition to Disease; Histones; Maternal Nutritional Physiological Phenomena; Nutritional Status; Ovalbumin; Pregnancy; Promoter Regions, Genetic; Rats, Sprague-Dawley; Risk Factors

The current paradigm describing asthma pathogenesis recognizes the central role of abnormal epithelial function in the generation and maintenance of the disease. However, the mechanisms responsible for the initiation of airway remodeling, which contributes to decreased lung function, remain elusive. Therefore, we aimed to determine the role of altered pulmonary gene expression in disease inception and identify proremodeling mediators.. Using an adenoviral vector, we generated mice overexpressing smad2, a TGF-β and activin A signaling molecule, in the lung. Animals were exposed to intranasal ovalbumin (OVA) without systemic sensitization.. Control mice exposed to inhaled OVA showed no evidence of pulmonary inflammation, indices of remodeling, or airway hyper-reactivity. In contrast, local smad2 overexpression provoked airway hyper-reactivity in OVA-treated mice, concomitant with increased airway smooth muscle mass and peribronchial collagen deposition. Pulmonary eosinophilic inflammation was not evident, and there was no change in serum IgE or IgG1 levels. The profound remodeling changes were not mediated by classical pro-inflammatory Th2 cytokines. However, uric acid and interleukin-1β levels in the lung were increased. Epithelial-derived endothelin-1 and fibroblast growth factor were also augmented in smad2-expressing mice. Blocking endothelin-1 prevented these phenotypic changes.. Innate epithelial-derived mediators are sufficient to drive airway hyper-reactivity and remodeling in response to environmental insults in the absence of overt Th2-type inflammation in a model of noneosinophilic, noninflammed types of asthma. Targeting potential asthma therapies to epithelial cell function and modulation of locally released mediators may represent an effective avenue for therapeutic design.

Topics: Airway Remodeling; Animals; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; Endothelin-1; Female; Gene Expression; Inflammation Mediators; Mice; Mice, Transgenic; Muscle, Smooth; Ovalbumin; Respiratory Mucosa; Smad2 Protein

We examined the contribution of p70 ribosomal S6 kinase (p70S6K) to airway smooth muscle hypertrophy, a structural change found in asthma. In human airway smooth muscle cells, transforming growth factor (TGF)-beta, endothelin-1, and cardiotrophin-1 each induced phosphorylation of p70S6K and ribosomal protein S6 while increasing cell size, total protein synthesis, and relative protein abundance of alpha-smooth muscle actin and SM22. Transfection of myocytes with siRNA against either p70S6K or S6, or infection with retrovirus encoding a kinase-dead p70S6K, reduced cell size and protein synthesis but had no effect on contractile protein expression per mg total protein. Infection with a retrovirus encoding a constitutively active, rapamycin-resistant (RR) p70S6K increased cell size but not contractile protein expression. siRNA against S6 decreased cell size in myocytes expressing RR p70S6K. Finally, TGF-beta treatment, but not RR p70S6K expression, increased KCl-induced fractional shortening. Together, these data suggest that p70S6K activation is both required and sufficient for airway smooth muscle cell size enlargement but not contractile protein expression. Further, ribosomal protein S6 is required for p70S6K-mediated cell enlargement. Finally, we have shown for the first time in a functional cell system that p70S6K-mediated myocyte enlargement alone, without preferential contractile protein expression, is insufficient for increased cell shortening.

Topics: Airway Remodeling; Animals; Asthma; Cell Enlargement; Cells, Cultured; Contractile Proteins; Cytokines; Disease Models, Animal; Endothelin-1; Enzyme Activation; Humans; Hypertrophy; Lung; Mice; Mice, Inbred BALB C; Microfilament Proteins; Muscle Contraction; Muscle Proteins; Muscle, Smooth; Mutation; Myocytes, Smooth Muscle; Ovalbumin; Phenotype; Phosphorylation; Potassium Chloride; Ribosomal Protein S6; Ribosomal Protein S6 Kinases, 70-kDa; RNA Interference; Transduction, Genetic; Transforming Growth Factor beta

The first genome wide association study (GWAS) for childhood asthma identified a novel major susceptibility locus on chromosome 17q21 harboring the ORMDL3 gene, but the role of previous asthma candidate genes was not specifically analyzed in this GWAS. We systematically identified 89 SNPs in 14 candidate genes previously associated with asthma in >3 independent study populations. We re-genotyped 39 SNPs in these genes not covered by GWAS performed in 703 asthmatics and 658 reference children. Genotyping data were compared to imputation data derived from Illumina HumanHap300 chip genotyping. Results were combined to analyze 566 SNPs covering all 14 candidate gene loci. Genotyped polymorphisms in ADAM33, GSTP1 and VDR showed effects with p-values <0.0035 (corrected for multiple testing). Combining genotyping and imputation, polymorphisms in DPP10, EDN1, IL12B, IL13, IL4, IL4R and TNF showed associations at a significance level between p = 0.05 and p = 0.0035. These data indicate that (a) GWAS coverage is insufficient for many asthma candidate genes, (b) imputation based on these data is reliable but incomplete, and (c) SNPs in three previously identified asthma candidate genes replicate in our GWAS population with significance after correction for multiple testing in 14 genes.

Topics: Adolescent; Alleles; Asthma; Child; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Endothelin-1; Female; Gene Frequency; Genetic Predisposition to Disease; Genome-Wide Association Study; Genotype; Glutathione S-Transferase pi; Humans; Interleukin-12 Subunit p40; Interleukin-13; Interleukin-4; Interleukin-4 Receptor alpha Subunit; Male; Membrane Proteins; Polymorphism, Single Nucleotide; Tumor Necrosis Factor-alpha

Severe asthma is a highly incapacitating disease with no effective preventive or curative treatment. The 10% of patients with "refractory" or "difficult" asthma have chronic symptoms, episodic exacerbations and persistent airway obstruction, despite chronic? 2-agonist and steroid therapy. A major objective of current asthma research is to identify the underlying cellular and molecular mechanisms and thus to develop new treatments. Persistent airway eosinophilia is a hallmark of severe asthma. IL-5 is essential for terminal differentiation of committed eosinophil precursors and is also involved in eosinophily degranulation and priming. By releasing cytokines and cationic proteins, eosinophils contribute to airway inflammation and damage the bronchial mucosa. A monoclonal antibody against IL-5 has been shown to reduce exacerbations of refractory asthma. Interventions targeting eosinophil cationic proteins might have therapeutic potential. Structural changes in the bronchial wall, collectively known as airway remodeling, are believed to play a prominent role in the persistent airflow obstruction associated with severe asthma. In this setting the airway epithelium shows major abnormalities, including loss of barrier function, phenotypic changes, and functional disorders. The abnormal respiratory epithelium is believed to orchestrate airway remodeling through aberrant production of extracellular matrix components, fibrogenic cytokines and chemokines, and growth factors responsible for the proliferation, migration and activation of smooth muscle cells and fibroblasts. Recently, increased ET-1 synthesis by the bronchial epithelium was observed in severe refractory asthma, and was found to correlate with airway remodeling and airway obstruction. ET-1 might represent a novel therapeutic target in severe steroid-refractory asthma.

Topics: Anti-Asthmatic Agents; Antibodies, Monoclonal; Asthma; Endothelin-1; Eosinophilia; Humans; Receptors, Tumor Necrosis Factor; Respiratory Mucosa; Severity of Illness Index

To observe the effect of Wenyang Yiqi Pingchuan Recipe (WYPR) on the pathomorphology of lung and its regulation on lung tissue contents of nitric oxide (NO) and endothelin-1 (ET-1) in rats with bronchial asthma.. Sixty SD rats were randomly divided into 6 groups: the normal group, the model group, and the four treated groups treated with high dose WYPR, low dose WYPR, Guilong Kechuanning Capsule and aminophylline, respectively, 10 in each group. Except those in the normal group, all rats of bronchial asthma model were established by egg protein sensitization and provocated by inhalation. The treatments were given via gastrogavage every day starting from the first provocation (the 3rd week of modeling) to the execution. Rats were sacrificed after 4-week treatment, their lung was taken for determining the contents of NO and ET-1, and histopathological changes in lung were observed as well.. Compared with the normal group, the contents of NO and ET-1 in the lung tissue, the thickness of bronchus wall and bronchus smooth muscle, the number of eosinophil granulocytes increased in the model group and the low dose WYPR group, showing statistical significance (P < 0. 01). As compared with the model group, all the above-mentioned indices were lower in all the 4 treated groups (P < 0.05 or P < 0.01), but the lowering in the WYPR treated groups (either high or low dose) was more significant than in the Guilong Kechuanning treated group (P < 0.05 or P < 0.01); while compared with the aminophylline treated group, the high dose WYPR group was superior in reducing eosinophile granulocytes (P < 0.01), but no significance between them was shown in NO and ET-1 levels (P > 0.05).. WYPR could reduce the eosinophilic infiltration, decrease the contents of NO and ET-1 in the lung tissue, restrain the air passage inflammation and inhibit the pathological process as airway remodeling.

Topics: Animals; Asthma; Drugs, Chinese Herbal; Endothelin-1; Inflammation; Lung; Nitric Oxide; Rats; Rats, Sprague-Dawley

Endothelin-1 (EDN1) has been reported to be implicated in the pathophysiology of asthma. Literature results on the genetic association of EDN1 in asthma are inconsistent. Eleven single nucleotide polymorphisms in EDN1 were genotyped in 342 and 100 families from UK and Norway, respectively. Asthma, bronchial hyperreactivity (BHR) and atopic asthma phenotypes were analyzed for the family-based association. Five single nucleotide polymorphisms (SNPs) were associated with asthma (0.0017

Topics: Adolescent; Adult; Alleles; Asthma; Case-Control Studies; Child; Data Interpretation, Statistical; Endothelin-1; Family; Female; Gene Frequency; Genetic Markers; Genetics, Population; Haplotypes; Humans; Linkage Disequilibrium; Male; Norway; Polymorphism, Single Nucleotide; Statistics as Topic; United Kingdom

Endothelins are proinflammatory, profibrotic, broncho- and vasoconstrictive peptides, which play an important role in the development of airway inflammation and remodeling in asthma. The study was undertaken to evaluate the endothelin-1 (ET-1) levels in exhaled breath condensate (EBC) of asthmatics with different degree in asthma severity. EBC was collected from 31 patients with allergic asthma (11 with steroid-naïve mild asthma, 10 with ICS-treated, stable mild-to-moderate asthma, 10 with ICS-treated unstable, severe asthma) and 7 healthy volunteers. In the three groups of asthmatics, ET-1 concentrations in EBC were significantly higher than in healthy volunteers. ET-1 levels were significantly higher in patients with unstable asthma than in the two groups with stable disease. There was a significant correlation between ET-1 levels and FENO in the three groups of asthmatics and between ET-1 and blood eosinophil counts in the group of patients with unstable asthma. Measurements of ET-1 in EBC may provide another useful diagnostic tool for detecting and monitoring inflammation in patients with asthma.

Topics: Adult; Asthma; Breath Tests; Bronchial Hyperreactivity; Case-Control Studies; Endothelin-1; Female; Humans; Inflammation Mediators; Male; Middle Aged; Nitric Oxide

Airway remodeling and associated angiogenesis are documented features of asthma, of which the molecular mechanisms are not fully understood. Angiotensin (ANG)II and endothelin (ET)-1 are potent vasoconstricting circulatory hormones implicated in asthma. We investigated the effects of ANG II and ET-1 on human airway smooth muscle (ASM) cells proliferation and growth and examined the mRNA expression and release of the angiogenic peptide, vascular endothelial growth factor (VEGF). Serum deprived (48 h) human ASM cells were incubated with ANG II (100 nM) or ET-1 (10 nM) for 30 min, 1, 2, 4, 8, 16, and 24 h and the endogenous synthesis of VEGF was examined in relation to control cells receiving serum free culture medium. ET-1 induced time dependent DNA biosynthesis as determined by [3H]-thymidine incorporation assay. Using northern blot hybridization, we detected two mRNA species of 3.9 and 1.7 kb encoding VEGF in the cultured smooth muscle cells. Both ANG II and ET-1 induced the mRNA expression (two- to threefold) and secretion (1.8- to 2.8-fold) of VEGF reaching maximal levels between 4-8 h of incubation. Induced expression and release of VEGF declined after 8 h of ANG II incubation while levels remained elevated in the case of ET-1. The conditioned medium derived from ET-1-treated ASM cells induced [3H]-thymidine incorporation and cell number in porcine pulmonary artery endothelial as well as human umbilical vein endothelial cells. Moreover, the VEGF tyrosine kinase receptor inhibitor blocked the conditioned medium induced mitogenesis in endothelial cells. Our results suggest a potential role for ANG II and ET-1 in ASM cell growth and upregulation of VEGF that may participate in endothelial cell proliferation via paracrine mechanisms and thus causing pathological angiogenesis and vascular remodelling seen during asthma.

Topics: Angiotensin II; Animals; Asthma; Cell Proliferation; Culture Media, Conditioned; Endothelin-1; Endothelium, Vascular; Gene Expression Regulation; Humans; Myocytes, Smooth Muscle; Neovascularization, Pathologic; Peptides; Swine; Trachea; Vascular Endothelial Growth Factor A

Bronchial asthma is a chronic inflammatory disease of the respiratory tract where variety of cells plays a role, particularly mast cells, eosinophils (Eo), and T lymphocytes. At present, there is no clear-cut clinical or laboratory parameter to monitor the activity of this disease. Our study was designed to examine and compare serum eosinophilic cationic protein (S-ECP) levels, plasma ET-1 (P-ET) levels and percentage of eosinophils with CD44 (EoCD44) in paediatric asthmatic patients.. In our study, a group of 97 atopic children with persisting mild asthma, had a detailed analysis of their personal history. In addition, S-ECP, P-ET, EoCD44, eosinophil blood count (Eo) and serum levels of IgE(S-IgE) in peripheral blood were determined. Subsequently, children were treated with montelukast (singular), a leukotriene receptor antagonist for a period of three weeks (montelukast tablets in a dose of 5 mg once a day). A second S-ECP, P-ET, EoCD44 were determined in the interval of 3 months from the first collection. In 97 asthmatic children a correlation between P-ET and EoCD44 (p=0.002; r= -0.5) were found.. Our follow-up study surprisingly confirmed a correlation between P-ET and EoCD44. The lower percentage of EoCD44 in peripheral blood in asthmatic children is due to Eo inflammation activity and attests the massive Eo invasion into the airways. The determination of combination - S-ECP, P-ET, EoCD44 - provides an indirect evidence of the multiple features of Eo inflammation.

Topics: Adolescent; Asthma; Child; Child, Preschool; Endothelin-1; Eosinophil Cationic Protein; Eosinophils; Female; Humans; Hyaluronan Receptors; Inflammation; Male

Airway remodeling in patients with severe steroid-refractory asthma might result from a reduced ability of steroid therapy to limit the transcription of remodeling factors by the bronchial epithelium.. We sought to compare the levels of transcripts encoding remodeling factors in bronchial epithelium of healthy volunteers and of asthmatic patients with either steroid-sensitive or steroid-refractory disease and to correlate these levels with hallmarks of airway remodeling.. By means of real-time quantitative PCR, we assessed the levels of 14 transcripts encoding remodeling factors, matrix metalloproteinases, and extracellular matrix proteins in laser-capture microdissected bronchial epithelium of healthy volunteers, patients with mild steroid-untreated asthma, and patients with steroid-sensitive and steroid-refractory asthma (n = 8-10 in each group). Histologic features of airway remodeling and endothelin-1 (EDN1) immunolocalization were determined by using frozen specimens.. Patients with steroid-refractory asthma had greater levels of EDN1 transcripts (4.1-fold increase, P = .026) and protein (P = .0009) in their bronchial epithelium compared with patients with steroid-sensitive asthma. EDN1 mRNA levels and protein expression in asthmatic patients were negatively correlated with prebronchodilator and postbronchodilator FEV(1) value (r(2) >or= 0.193, P

Topics: Adjuvants, Immunologic; Anti-Inflammatory Agents; Asthma; Bronchi; Dyspnea; Endothelin-1; Gene Expression Regulation; Humans; Respiratory Mucosa; Steroids

Four hundred patients with bronchial asthma (BA) were questioned. Complex clinical and instrumental examination of 60 patients with BA and endoscopic-positive gastroesophageal reflux disease was carried out; the control groups included 30 patients with BA alone and 30 patients with GERD alone. Clinical symptoms of GERD were revealed in 58% of BA patients; endoscopic-positive GERD was diagnosed in 48.6% of BA patients. The study proved the connection between the degree of respiratory disturbances, on the one hand, and the degree of esophagitis and the level of intraesophageal pH, on the other, in patients with BA plus GERD. The study also established the role of esophageal and gastric epitheliocytes, producing endothelin-1, melatonin, NO-synthase, and calretinin, in the occurrence of mutual exacerbation syndrome.

Topics: Adult; Algorithms; Asthma; Calbindin 2; Endothelin-1; Esophagus; Female; Gastroesophageal Reflux; Humans; Male; Melatonin; Nitric Oxide Synthase; S100 Calcium Binding Protein G; Severity of Illness Index; Stomach

The peptide, endothelin-1 (ET-1) regulates proliferative responses in numerous cell types. Recently, a dual ET receptor antagonist was shown to prevent the increase in airway smooth muscle cell (SMC) proliferation that accompanies airway smooth muscle remodeling in a rat model of experimental asthma. Thus, we used [(3)H]-thymidine incorporation assays and western immunoblotting to identify signaling pathways that regulate proliferative responses in cultured rat tracheal SMC. Our data indicate that ET-1 activation of the ET A receptor subtype induced [(3)H]-thymidine incorporation and activation of ERK 1/2 in primary rat tracheal SMC. ET-1-induced [(3)H]-thymidine incorporation and activation of ERK 1/2 were inhibited by pretreatment of SMC with pertussis toxin or down regulation of phorbol ester responsive isoforms of PKC. While ET- 1-induced ERK 1/2 activation was unaffected following inhibition of Rho kinase, ET-1-induced [(3)H]-thymidine incorporation was abrogated. ET-1 also potentiated [(3)H]-thymidine incorporation as well as cell proliferation of SMC stimulated with PDGF-BB and this response did not appear to be regulated by ERK1/ 2. These data demonstrate that ET-1 induces activation of multiple G proteins that regulate rat tracheal SMC proliferative responses, likely through signaling pathways downstream of ERK1/2 and Rho kinase.

Topics: Animals; Asthma; Cell Proliferation; Cells, Cultured; Drug Synergism; Endothelin-1; GTP-Binding Proteins; Humans; MAP Kinase Signaling System; Models, Biological; Muscle, Smooth; Platelet-Derived Growth Factor; Rats; Receptor, Endothelin A; Signal Transduction; Thymidine; Trachea

To study the effects of different fractions of Modified Zhisousan (MZ, MZC, MZS) on the contents of nitric oxide (NO), endothelin-1 (ET-1) and eosinophilia (EOS) in the allergic asthma guinea pigs and observe the pathology changes of lung tissue.. The number of EOS in the blood and bronchialveolar lavage fluid (BALF) was counted by Wright staining. The contents of ET-1 and No in serum and BALF were analyzed by RIA and nitric acid reductase method. The guinea pig lungs were observed under the optical and electron microscope.. The number of EOS and the contents of ET-1 and NO in model group were higher than those in control group (P < 0.01). The pathological changes of lung were obvious. The number of EOS and the contents of ET-1 and NO were descended remarkably (P < 0.05 or P < 0.01) and the pathological changes in the lung tissue were lightened obviously in MZ and MZC groups, but MZS group had no such effects.. MZC is the effective part of MZ and the anti-asthmatic mechanisms ware related to its significant reduction in contents of ET-1, NO, EOS and the damage of lung tissue possibly.

Topics: Animals; Anti-Asthmatic Agents; Asthma; Bronchoalveolar Lavage Fluid; Drugs, Chinese Herbal; Endothelin-1; Eosinophils; Guinea Pigs; Leukocyte Count; Lung; Mice; Nitric Oxide; Powders

The bronchoconstrictive peptide endothelin-1 (ET-1) has been demonstrated in the airway epithelial and endothelial cells. In this study we investigated the pathophysiological significance of endothelin-1 in asthma. We addressed the issue by assessing the concentration of ET-1 in plasma and bronchoalveolar lavage fluid (BALF) in patients with a different intensity of asthma. Twenty one asthmatic patients (11 men,10 women) and 6 healthy control subjects (C) were included in the study. Eleven asthmatic patients were classified as moderate persistent asthma (SA), all of them were atopic, and another 10 were mild persistent asthmatics (AA). Lung function tests were carried out in all patients investigated. The ET-1 concentration was determined by an ELISA method in plasma and BALF. We found that the SA patients had the highest level of ET-1 (SA - 11.4 +/-3.6 fmol/ml; AA - 7.1 +/-2.7 fmol/ml; C - 5.6 +/-1.8 fmol/ml) in BALF. The same concerned the ET-1 level in plasma (SA - 27.8 +/-3.8 fmol/ml; AA - 18.1 +/-4.3 fmol/ml; C - 17.3 +/-3.0 fmol/ml). A positive correlation between the plasma ET-1 level and lung function indices was observed. We conclude that the higher levels of ET-1 in more severe asthma suggest that endothelins may contribute to the pathophysiology of the disease, its severity, and the regulation of bronchial tone.

Topics: Adolescent; Adult; Asthma; Bronchoalveolar Lavage Fluid; Endothelin-1; Female; Forced Expiratory Volume; Humans; Male

In investigation were included 33 children with mild and moderate bronchial asthma of atopic geneses, average duration of the disease 3,5+/-1,9 years, average frequency of asthma attacks was less then once per month (night attacks 2-3 times per week), factors of initiation were dust and sharp smells. It was shown, that in atopic bronchial asthma in children, disbalance in endothelial system is developed, the content of endothelin-1, vasoconstrictor peptide of endotheliocytes, is increased by 64%. At the same time, coefficient of correlation between redox-potential NADP/NADPH and content of IgE decreases from 0,79 (p<0,01) in norm to 0,57 (p<0,05). Obtained data raises the issue of necessity of inclusion in the therapy of bronchial asthma the remedies which prevent bioenergetic failure.

Topics: Asthma; Child; Child, Preschool; Dermatitis, Atopic; Endothelin-1; Female; Humans; Hypoxia; Immunoglobulin A; Immunoglobulin E; Male; Oxidation-Reduction; Skin

To address the possible role of injured airway epithelium in initiating transdifferentiation of sub-epithelial fibroblasts into myofibroblasts and accelerating cell proliferation in sub-epithelial fibroblasts, which may be involved in airway hyperresponsiveness in asthma.. Human primary cultured sub-epithelial fibroblasts were co-cultured with human bronchial epithelial cells (16HBE) which were treated with lipopolysaccharide (LPS) plus mechanical scratch prior to co-culture. The procedure was also performed in the presence or absence of endothelin (ET) receptor A inhibitor (BQ123), transforming growth factor-beta(1) (TGF-beta(1)) neutralized antibody, respectively or simultaneously, followed by immunostaining, Western blotting and bromodeoxyuridine (BrdU) incorporation respectively to detect alpha-SMA expression and cell proliferation in the co-cultured sub-epithelial fibroblasts. Using the inhibitors specific for mitogen-activated protein kinases (MAPKs) pathways, the role of MAPKs pathways in activating the expression of alpha-SMA was evaluated. In addition, the interaction between matrix metalloproteinases (MMPs) and ET-1 was investigated by cell transfection with anti-ET-1 converting enzyme (anti-ECE) mRNA expression plasmid followed by gelatin zymography analysis.. 16HBE treated with LPS plus mechanical injury induced alpha-SMA expression in sub-epithelial fibroblasts and accelerated BrdU incorporation in the cells. BQ123, TGF-beta(1) neutralized antibody, specific inhibitors for p38 MAPK and extracellular signal-regulated kinase 1/2 (ERK1/2) were able to block the induction respectively to a certain extent. Phosphorylated p38 MAPK and ERK1/2 were detected in the sub-epithelial fibroblasts 10 min after being co-cultured with injured 16HBE. Compared to normal control (16HBE transfected with pEGFPN(2)) or those cells transfected with anti-ECE mRNA expression plasmids, ET-1 released from the 16HBE cells transfected with pEGFPN(2) into supernatants were increased significantly after the treatment described as above: 16HBE pre-transfected with pEGFP-N(2) expression plasmid before being treated with mechanical scrape plus LPS stimulation: (15.00 +/- 0.86) pg/ml; 16HBE pre-transfected with anti-ECE expression plasmid before being treated with mechanical scrape plus LPS stimulation: (7.57 +/- 0.94) pg/ml (all P < 0.01). At the same time, the activities of MMP-2 and MMP-9 were enhanced.. Injured airway epithelial cells induced the transdifferentiation of sub-epithelial fibroblasts into myofibroblasts, which may be mediated by ET-1 and TGF-beta(1) through MARKs pathways such as p38 MAPK and ERK 1/2.

Topics: Actins; Asthma; Cell Differentiation; Cell Line, Transformed; Cell Proliferation; Cell Transdifferentiation; Coculture Techniques; Endothelin-1; Epithelial Cells; Fibroblasts; Humans; Lipopolysaccharides; Mitogen-Activated Protein Kinase 3; p38 Mitogen-Activated Protein Kinases; Peptides, Cyclic; Phosphorylation; Protein Kinase Inhibitors; Respiratory Mucosa; Transfection; Transforming Growth Factor beta1

To evaluate the inhibiting effect of niflumic acid (NFA), an inhibitor of calcium-activated chloride channel (ClCa) on airway epithelium, on the airway hyperresponsiveness in asthmatic mice.. BALB/c mice were randomly divided into an asthma group (A group), a NFA prevention asthmatic group (B group) and a sham-challenged group (C group). The airway pressure time index (APTI) and the content of ET-1 and NO in bronchoalveolar lavage fluid (BALF) in all groups were measured. With the isolated tracheal rings with integral epithelium or epithelium removed from the asthma group (A(1) group and A(2) group) and the sham-challenged group (C(1) group and C(2) group), the contractile responsiveness of various rings to methacholine (mACh) was examined, and its change was observed when the rings were exposed to NFA beforehand.. Compared with A group (1.62 +/- 0.14), the APTI in B group (1.21 +/- 0.07) was reduced remarkably (P < 0.01), and the contents of ET-1 [(103 +/- 9) ng/L] and NO [(48.5 +/- 3.2) micromol/L] in BALF of A group were significantly higher than those in B group, [(53 +/- 5) ng/L, (23.7 +/- 2.5) micromol/L (P < 0.01), respectively]. The ratios of maximum contractility in A(1), A(2), C(1) and C(2) groups were (3.79 +/- 0.44), (2.15 +/- 0.21), (1.26 +/- 0.14) and (2.06 +/- 0.18), respectively. The contractility of A(1) group was highest among all groups (all P < 0.01), but could be effectively decreased by NFA.. By inhibiting the special ClCa on the airway epithelium, NFA can inhibit the production of ET-1 and NO by epithelium and thus exert preventive effect on airway hyperresponsiveness in asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Endothelin-1; In Vitro Techniques; Male; Mice; Niflumic Acid; Nitric Oxide; Trachea

Asthma is a chronic airway disease, known to involve several inflammatory mediators. Little is known about how these mediators interact in order to produce or attenuate even basic features of the disease, like airway hyper-reactivity and remodelling. Endothelin-1 (ET-1) and IL-1beta are two mediators suggested to play important roles in the induction of airway inflammation.. To investigate the interactions between ET-1 and IL-1beta, using a novel in vitro model of asthma, focusing on airway smooth muscle contractility.. Isolated murine tracheal segments were cultured from 1 to 8 days in the absence and presence of IL-1beta. The subsequent contractile responses to sarafotoxin 6c (S6c) (selective agonist for ETB receptor) and sarafotoxin 6b (S6b) (ETA and ETB receptor agonist) were recorded by a myographs system. In all experiments, ETB receptors were desensitized before the contractile response to S6b was recorded. Thus, the response to S6b is only mediated by ETA receptors in the present study. The mRNA expressions for ET-1 and endothelin (ET) receptors were quantified by real-time PCR.. Organ culture in the presence of IL-1beta attenuated the maximal contraction induced by S6c, but not S6b. This reduction was concentration-dependent and was significant after 2, 4 and 8 days of culture. To investigate the mechanisms behind this, inhibitors for endothelin converting enzyme (ECE) phosphoramidon, c-JUN N-terminal kinase (JNK) SP600125, extracellular-signal-regulated kinase 1/2(ERK 1/2) PD98059 and p38 pathway SB203580 were used. Individually, SP600125 and PD98059, but not SB203580, could partly reverse the reduction induced by IL-1beta. An additional effect was obtained when SP600125 and PD98059 were combined. The mRNA expressions for ET-1 and ETB receptor were up- and down-regulated, respectively, by IL-1beta.. Presence of IL-1beta in the airways attenuate the contractile response mediated via ETB receptors, an effect dependent on ECE, JNK and ERK 1/2 pathways.

Topics: Animals; Aspartic Acid Endopeptidases; Asthma; Disease Models, Animal; Endothelin-1; Endothelin-Converting Enzymes; Extracellular Signal-Regulated MAP Kinases; Interleukin-1; JNK Mitogen-Activated Protein Kinases; Male; Metalloendopeptidases; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; Muscle Contraction; Muscle, Smooth; Organ Culture Techniques; p38 Mitogen-Activated Protein Kinases; Receptor, Endothelin A; Receptor, Endothelin B; RNA, Messenger; Time Factors; Trachea; Vasoconstrictor Agents; Viper Venoms

To study the anti-asthmatic effect of sodium ferulate (SF) and its mechanism in guinea pig asthmatic model.. Guinea pigs were sensitized with ovalbumin as animal asthmatic model and treated with 3 different concentration of SF for 8 days. Levels of endothelin (ET) and nitric oxide (NO) in blood and lung tissue, and eosinophil (EOS) in blood and bronchoalveolar lavage fluid (BLAF) was counted at the end of trial.. SF could significantly lower the ET content and increase the NO concentration in serum and lung tissue, reduce the number of EOS in blood and BLAF (P < 0.05, P < 0.01). Stronger effect was showed in the high dose group.. Mechanism of anti-asthmatic action of SF might be to increase NO concentration, lower ET content, alleviate EOS infiltration.

Topics: Animals; Anti-Asthmatic Agents; Asthma; Bronchoalveolar Lavage Fluid; Coumaric Acids; Endothelin-1; Eosinophils; Female; Guinea Pigs; Male; Nitric Oxide; Ovalbumin

To determine a change in airway smooth muscle contractility in a murine model of allergic asthma, the responsiveness of airway smooth muscles isolated from ovalbumin (OA)-sensitized and -challenged mice was compared with that from control animals.. Actively sensitized mice were repeatedly challenged by ovalbumin (OA) antigen inhalation. Twenty-four h after the last antigen challenge, tracheal and bronchial smooth muscle responsiveness to acetylcholine (ACh) and endothelin-1 (ET-1) were measured. Airway microvascular leakage and histochemistry were also determined as indices of airway inflammation.. Both the ACh and ET-1 responsiveness of bronchial, but not tracheal, smooth muscles were significantly augmented in OA-challenged mice, whereas no significant change in the expression levels of M2, M3 and ETB receptors was observed. The Evans blue dye extravasation in the main bronchial, but not tracheal, tissue of OA-challenged mice was significantly increased as compared with that of sensitized control animals. A marked inflammatory cells infiltration was also observed in bronchial but not tracheal tissues of OA-challenged mice.. Repeated antigen challenge to sensitized mice caused a hyperresponsiveness of bronchial, but not tracheal, smooth muscle accompanied with bronchial tissue inflammation.

Topics: Acetylcholine; Animals; Antigens; Asthma; Bronchi; Bronchial Hyperreactivity; Capillary Permeability; Disease Models, Animal; Endothelin-1; Immunization; Male; Mice; Mice, Inbred BALB C; Muscle Contraction; Muscle, Smooth; Ovalbumin; Receptor, Endothelin B; Receptor, Muscarinic M1; Receptor, Muscarinic M2; Trachea

Transforming growth factor-beta (TGF-beta) and endothelin (ET) are found in elevated amounts in the airways of individuals with asthma. The cellular source of these peptides and their role in mediating the airway fibrosis of chronic asthma are unknown. In response to mechanical stresses similar to those occurring in vivo during airway constriction, bronchial epithelial cells increase the steady-state level of mRNA for both ET-1 and ET-2, followed by increased release of ET protein. Mechanical stress also enhances release of TGF-beta2 from a preformed cell-associated pool. TGF-beta2 and ET act individually and, more importantly, synergistically to promote fibrotic protein synthesis in reporter fibroblasts. To confirm the role of these intermediates in stress-induced fibrosis, conditioned medium from mechanically stressed bronchial epithelial cells was shown to elicit fibrotic protein synthesis in reporter fibroblasts; this effect was significantly inhibited by combined treatment with ET receptor antagonists and a neutralizing antibody to TGF-beta2. These data are consistent with a primary pathogenic role for mechanical stress-induced release of both TGF-beta2 and ET in the subepithelial fibrosis that characterizes chronic asthma.

Topics: Asthma; Bronchi; Cells, Cultured; Culture Media, Conditioned; Endothelin-1; Endothelin-2; Epithelial Cells; Fibrosis; Humans; Protein Biosynthesis; RNA, Messenger; Stress, Mechanical; Transforming Growth Factor beta; Transforming Growth Factor beta2

Endothelin-1 (ET-1) has been implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). The ET-1 levels are elevated during exacerbations of asthma and COPD in bronchoalveolar lavage, serum, and sputum and fails with treatment of the exacerbations. Hypoxemia stimulates ET-1 secretion.. The aim of this study was to examine the serum ET-1 levels in stable asthmatic and COPD patients.. We examined 48 COPD and 26 asthmatic patients and 34 normal subjects. We collected arterial samples to measure baseline ET-1 levels in all patients and in the control group, during the day. All the patients underwent formal polysomnography (EEG, ECG, airflow, respiratory muscle movement, oximeter) to detect the presence of nocturnal, nonapneic, and oxyhemoglobin desaturation. Twelve of the COPD patients and six of the asthmatic patients were disqualified because of inadequate sleep or sleep apnea syndrome. Nineteen of the COPD patients desaturated below a baseline sleep saturation of 90% for 5 min or more, reaching a nadir saturation of at least 85%. We collected arterial samples to measure ET-1 levels, 5 min after the first period of desaturation in each of the 19 desaturators COPD patients. None of the 20 asthmatic patients exhibited oxyhemoglobin desaturation during sleep.. Baseline arterial ET-1 levels during the day were significantly higher in "desaturators" COPD patients (2.08+/-0.28 pg/ml) compared to "non-desaturators" COPD patients (1.38+/-0.16 pg/ml) (P<0.001) and to asthmatics (0.7+/-0.85 pg/ml) (P<0.001). ET-1 Levels in normal subjects were 1.221+/-0.02 pg/ml. In "desaturators" COPD patients ET-1 levels during the night, 5 min after the first oxyhemoglobin desaturation, were significantly higher (4.28+/-1.10 pg/ml) compared to those during the day (2.08+/-0.28 pg/ml) (P<0.001). A significant negative correlation was observed between ET-1 levels and degree of desaturation during the day (P=0.005, r=0.632) and during the night (P<0.001, r=0.930) in "desaturators" COPD patients.. According to our results: (1) ET-1 levels were significantly higher in "desaturators" COPD patients than in "non-desaturators" COPD and in asthmatics; (2) ET-1 levels were significantly higher during the night than during the day in "desaturators" COPD patients; (3) the degree of desaturation correlated negatively with the ET-1 levels in "desaturators" COPD patients, both during daytime and nighttime. These findings are consistent with the hypothesis that ET-1 is implicated in the pathophysiology of asthma and COPD, especially if nocturnal, nonapneic, oxyhemoglobin desaturation exists.

Topics: Asthma; Biomarkers; Endothelin-1; Forced Expiratory Volume; Humans; Middle Aged; Oxygen; Pulmonary Disease, Chronic Obstructive; Vital Capacity

The respiratory epithelium is a protective barrier that also functions as an interactive metabolically active component of the lung. The healing and repair of the epithelium involves initial migration of epithelial cells, and subsequent proliferation. The purpose of our study was to assess the effect of inflammatory mediators, in particular endothelin-1 (ET-1), on bronchial epithelial cell proliferation and migration. Under the conditions studied, ET-1 slows proliferation of human bronchial epithelial cells, compared to control (p < 0.01). The presence of ET-1 results in slower migration of epithelial cells compared to control (p < 0.04). Based on these in vitro findings, ET-1 could potentially lead to inhibition of repair of the lung epithelium and enhanced remodeling.

Topics: Asthma; Bronchi; Cell Division; Cell Line; Cell Movement; Endothelin-1; Epithelial Cells; Humans; Respiratory Mucosa

As recent studies prove, endothelial cells and particularly one of their products, endothelin, are not only active agents taking part in sustaining homeostasis in the peripheral blood system, but are also involved in immunological responses and angiogenesis. This is especially true about endothelin, which is a powerful spasmogen and comitogen, in particular for the smooth muscles of the bronchi. Endothelial cells play an important role in angiogenesis of the lungs, observed in asthmatic patients. The marker of the condition of endothelium is von Willebrand factor (vWF). The aim of this research was to study the three elements (endothelial cells, endothelin, vWF) in peripheral blood of asthmatic patients. The study group consisted of 27 asthmatic patients (moderate and severe asthma) and 15 healthy individuals. Immunological method employing specific monoclonal antibodies was used to assess endothelial cells; immunoenzymatic method was used to assess endothelin and vWF. The concentration of endothelin in the blood of asthmatic patients was much higher than in the control group (1.02 +/- 2.13 vs 0.45 +/- 0.14), but the difference was not statistically significant. The numbers of circulating endothelial cells were significant higher in asthmatics than in healthy individuals (1.3 +/- 0.7 vs 0.48 +/- 0.3) and the concentrations of vWF were the same in both groups (105.3 +/- 18.7 vs 102.8 +/- 32.2). Additionally, positive correlation was found between endothelin and endothelial cells, endothelin and vWF, as well as endothelial cells and vWF. The results suggest that endothelium and endothelin play an active part in the process of remodeling in asthma and may serve as a tool in the prognosis of remodeling.

Topics: Adult; Aged; Antibodies, Monoclonal; Asthma; Biomarkers; Case-Control Studies; Endothelin-1; Endothelium, Vascular; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; von Willebrand Factor

Topics: Animals; Asthma; Biomarkers; Bronchial Spasm; Child; Endothelin-1; Endothelium, Vascular; Epithelial Cells; Fibrosis; Humans; Inflammation; Lung; Mice; Mice, Transgenic

Endothelin-1 (ET-1) has been formerly demonstrated to have potent vasocontractile as well as bronchoconstrictor effects in vitro. This followup study was aimed to evaluate the possible changes in ET-1 levels in the plasma of asthmatic children, according to disease activity and severity.. Plasma ET-1 was estimated by enzyme-linked immunoadsorbent assay in 30 asthmatic patients (6 to 12 years old) during and after remission of an acute attack. Thirty age- and sex-matched healthy children were included as a control group.. Plasma ET-1 immunoreactivity was significantly increased in the asthmatic children during the attacks (17.2+/-6.9 pg/mL) in comparison to the levels during quiescence of symptoms (0.9+/-1.13 pg/mL). Further, both values were significantly higher than the control value (0.22+/-0.29 pg/mL). The severity of attacks as judged clinically and by peak expiratory flow rate measurement did not influence the plasma endothelin status; neither did the family history of atopy nor the absolute eosinophil count. However, serum total IgE levels could be positively correlated to the plasma endothelin concentrations measured after remission of the asthmatic attacks (P < 0.05).. Our findings reinforce the concept that ET-1 may be implicated in the pathogenesis of bronchoconstriction. This may encourage further studies on the value of ET-1 antagonism among alternative therapeutic modalities of childhood asthma.

Topics: Acute Disease; Asthma; Bronchial Spasm; Bronchoconstriction; Capillary Leak Syndrome; Case-Control Studies; Child; Convalescence; Endothelin-1; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Female; Fibronectins; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Male; Phospholipases A; Severity of Illness Index

Interleukin (IL)-4 and IL-13 are key proinflammatory cytokines in asthma. Studies in transgenic mice show that both cytokines cause inflammation, but only IL-13 causes subepithelial fibrosis, a characteristic feature of asthma. We compared the in vitro profibrogenic effects of IL-4 and IL-13 using bronchial fibroblasts from asthmatic subjects. In the presence of transforming growth factor (TGF)-beta the cells transformed into contractile myofibroblasts and expressed alpha-smooth muscle actin and procollagen I. IL-4 and IL-13 also stimulated proliferation, but were relatively ineffective in promoting myofibroblast transformation. TGF-beta was more potent than the cytokines in stimulating release of endothelin-1 and vascular endothelial growth factor, whereas IL-4 and IL-13 were more potent stimuli for eotaxin release. Although neither IL-4 nor IL-13 induced profibrotic responses, both cytokines caused a corticosteroid-insensitive stimulation of TGF-beta2 release from primary bronchial epithelial cells. These data indicate that epithelial activation by IL-13 or IL-4 plays a critical role in initiating remodeling through release of TGF-beta2. TGF-beta2 then activates the underlying myofibroblasts to secrete matrix proteins and smooth muscle and vascular mitogens to propagate remodeling changes into the submucosa. In contrast, direct activation of submucosal fibroblasts by IL-4 and IL-13 has a proinflammatory effect via eotaxin release and recruitment of eosinophils into the airways.

Topics: Actins; Adult; Asthma; Bronchi; Cell Division; Cells, Cultured; Chemokine CCL11; Chemokines, CC; Collagen Type I; Culture Media, Conditioned; Cytokines; Endothelial Growth Factors; Endothelin-1; Epithelial Cells; Fibroblasts; Gene Expression Regulation; Humans; Hypersensitivity, Immediate; Interleukin-13; Interleukin-4; Lymphokines; Protein Isoforms; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Several genome-wide screens for asthma and related phenotypes have been published to date but data on fine-mapping are scarce. For higher resolution we performed a fine-mapping study with 2 cM average spacing in often discussed asthma candidate regions (2p, 5q, 6p, 7p, 9q, 11p, and 12q) to narrow down the regions of interest. All participants of a Caucasian family study (97 families with at least two affected sib pairs) were genotyped for 49 supplementary polymorphic dinucleotide markers. Our results indicate increased evidence for linkage on chromosome 6p, 9q, and 12q. These candidate regions were further analyzed with SNP polymorphisms in the endothelin 1 (EDN1), lymphotoxin alpha (LTA), and neuronal nitric oxide synthase (NOS1) genes. In addition, IL4 -590C>T and IL10 -592C>A, localized on chromosomes 5q and 1q, respectively, have been analyzed for SNP association. Of the six SNPs tested, four revealed weak association with the examined phenotypes. These are the IL10 -592C>A SNP in the interleukin 10 gene (p=0.036 for eosinophil cell counts), the 4124T>C SNP in EDN1 (p=0.044 for asthma), the 3391C>T SNP in NOS1 with eosinophil cell counts (p=0.0086), and the 5266C>T polymorphism, also in the NOS1 gene, for high IgE levels (p=0.022). In summary, fine mapping data enable us to confine asthma candidate regions, while variants of EDN1 and NOS1, or nearby genes, may play an important role in this context.

Topics: Asthma; Chromosome Mapping; Chromosomes, Human; Endothelin-1; Eosinophils; Exons; Genetic Linkage; Genetic Predisposition to Disease; Genotype; Humans; Interleukin-10; Interleukin-4; Introns; Leukocyte Count; Lymphotoxin-alpha; Microsatellite Repeats; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Phenotype; Polymorphism, Single Nucleotide; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; White People

Endothelins are a family of peptide mediators that have a number of biological properties, including the ability to act as bronchoconstrictors and vasoconstrictors of isolated airways and vessels. Endothelin-1 (ET-1) is the more potent peptide compared with the other two peptides of the family. To examine a possible involvement of ET- 1 in the pathogenesis of asthma, we measured arterial ET-1 levels in 11 patients with atopic asthma during attack and during remission, and in 11 healthy control subjects. We also performed fiberoptic bonchoscopy and bronchoalveolar lavage (BAL) to measure ET-1 levels in the 11 asthmatic patients during remission, and in the 11 healthy control subjects. ET-1 concentrations in arterial blood and in BAL were measured by a radioimmunoassay method. Arterial ET-1 levels were very significantly higher in asthma attack (3.67 +/- 0.51 pg ml(-1)) and in asthma remission (2.65 +/- 10.62 pg ml(-1)) compared with those of the healthy controls (1.37 +/- 0.14 pg ml(-1)) (P < 0.001). Arterial ET-1 levels were also very significantly higher during asthma attack compared with those in asthma remission (P < 0.001). BAL ET-1 levels were significantly higher in asthma remission (0.73 +/- 0.53 pmol g(-1)) compared with those of the healthy controls (0.16 +/- 0.02 pmol g(-1)) (P < 0.05). No correlation was observed between arterial and BAL ET-1 levels, PaO2 and peak expiratory flow rate (PEFR). These data are consistent with the hypothesis that ET-1 contributes to the pathophysiology of asthma. However, it is likely that the true importance of this vasoconstrictor peptide will only be revealed by pharmacological studies with specific receptor antagonists.

Topics: Adolescent; Adult; Asthma; Biomarkers; Bronchoalveolar Lavage; Bronchoalveolar Lavage Fluid; Bronchoscopy; Endothelin-1; Female; Forced Expiratory Volume; Humans; Male; Peak Expiratory Flow Rate; Radioimmunoassay

Bronchial subepithelial fibrosis is an histological characteristic of asthma. Cytokines and other mediators, such as PDGF-BB, TGF-beta1 and ET-1 found in the asthmatic submucosa can potentially activate a repair process that leads to fibroblast proliferation and collagen synthesis. The mechanisms of modulation of the repair process leading to extracellular matrix deposition are still to be documented. In this study, we assessed the in vitro proliferation and collagen synthesis of bronchial fibroblasts isolated from normal and asthmatic subjects in response to ET-1, platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-beta1 alone or in combination, in the presence or absence of dexamethasone. The combination of ET-1 with one of the other two growth factors, or the triple combination, significantly increased DNA synthesis and collagen production of bronchial fibroblasts isolated from both normal and asthmatic subjects, but the same growth factors used separately had no significant effect on the same parameters. These results suggest that the simultaneous presence of ET-1, PDGF-BB and TGF-beta1 in both normal and asthmatic subjects is necessary to activate bronchial fibroblast proliferation and collagen synthesis. As these mediators are present in the submucosa of the asthmatic bronchi, they could be responsible, at least in part, for the accumulation of collagen in the mucosa.

Topics: Analysis of Variance; Asthma; Becaplermin; Bronchi; Case-Control Studies; Cell Division; Cells, Cultured; Dexamethasone; DNA; Endothelin-1; Fibroblasts; Glucocorticoids; Humans; Platelet-Derived Growth Factor; Procollagen; Proto-Oncogene Proteins c-sis; Transforming Growth Factor beta

Various peptidases, including angiotensin-converting enzyme (ACE), inactivate some inflammatory peptides that are considered to influence the pathogenesis of atopic diseases. This enzyme is also involved in the conversion or activation of 2 bronchoconstriction mediators: angiotensin II from angiotensinogen and endothelin (ET), respectively.. We tested a hypothesis that asthma or other atopic diseases are associated with insertion/deletion ACE, M235T angiotensinogen, and TaqI ET-1 gene polymorphisms.. A case-control approach was used in the study. Healthy subjects (141 persons) were used as control subjects, and 231 patients with histories of atopic asthma, allergic rhinitis, atopic dermatitis, or a combination thereof were studied. ACE genotype was determined by PCR, angiotensinogen M235T and ET-1 by PCR, and restriction analysis by AspI and TaqI, respectively.. We found the significant association of the insertion/deletion polymorphism of the ACE, as well as that of M235T polymorphism of the angiotensinogen genes, with the group of patients with atopic diseases ( P =.0025 and P =.0204, respectively). No difference was proved for the intron 4 (position 8000) polymorphism in the ET-1 gene when comparing the atopic patients with the control group (P =.1774). A significant difference was found between groups of patients with both asthma and rhinitis and patients without both respiratory atopic diseases (P =.0033).. It follows that the examined polymorphisms in the genes for ACE, angiotensinogen, and ET-1 could participate in the etiopathogenesis of atopic diseases.

Topics: Adolescent; Adult; Alleles; Angiotensinogen; Asthma; Case-Control Studies; Dermatitis, Atopic; Endothelin-1; Female; Gene Frequency; Genotype; Humans; Hypersensitivity, Immediate; Male; Middle Aged; Mutation, Missense; Peptidyl-Dipeptidase A; Point Mutation; Polymerase Chain Reaction; Polymorphism, Genetic; Restriction Mapping; Rhinitis, Allergic, Seasonal

Contractile responses to endothelin-1 (ET-1) were investigated in isolated trachea from rats previously exposed to chronic hypoxia (10% O(2)) or room air for 14 days. Concentration-response curves were constructed to ET-1 (10(-11)-3x10(-7)m ) in the presence and absence of the ET(A)receptor antagonist FR 139317 (10(-8), 10(-7)and 10(-6)m ), the ET(B)receptor antagonist BQ 788 (10(-6)and 3x10(-6)m ), the non-selective ET receptor antagonist SB 209670 (10(-7)and 10(-6)m ) and a combination of FR 139317 (10(-6)m ) and BQ 788 (10(-6)m ). Concentration-response curves were also conducted to the ET(B)receptor agonist sarafotoxin S6c (10(-11)-3x10(-7)m ). In addition, responses to ET-1 (10(-11)-3x10(-7)m ) were examined in the presence and absence of the nitric oxide synthase inhibitor, L-NAME. In control rat trachea, both FR 139317 and BQ 788 failed to inhibit ET-1-induced contractions and, indeed, FR 139317 (10(-8)m ) and BQ 788 actually potentiated responses. In trachea from chronic hypoxic rats, FR 139317 did not alter ET-1 responses whereas BQ 788 again potentiated ET-1-induced contractions. The non-selective ET receptor antagonist SB 209670 attenuated ET-1-evoked contractions in trachea from control and chronically hypoxic rats. A combination of FR 139317 (10(-6)m ) and BQ 788 (10(-6)m ) also attenuated ET-1 responses in control rat trachea, but not trachea from chronically hypoxic rats. In trachea from both control and chronically hypoxic rats, L-NAME significantly potentiated responses to ET-1. To investigate ET receptor-mediated relaxation, tissues were preconstricted with methacholine and concentration-response curves were conducted to ET-1 (10(-13)-10(-8)m ) in the presence and absence of BQ 788 (10(-6)m ) and to the ET(B)receptor agonist sarafotoxin S6c (10(-13)-10(-8)m ). In trachea from control and chronic hypoxic rats, ET-1 and sarafotoxin S6c evoked only very small, non-reproducible relaxatory responses.

Topics: Animals; Asthma; Bronchoconstriction; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Hypoxia; Male; NG-Nitroarginine Methyl Ester; Rats; Rats, Wistar; Receptors, Endothelin; Trachea

Endothelin-1 (ET-1) is a 21 amino acid peptide released from several types of bronchial cells. It operates through two types of receptors, type A(ET-RA) and type B(ET-RB) and has various activities in the pathophysiology of atopic asthma. These genes are localised on different chromosomes where genome-wide searches have identified linkage for atopic asthma, thus supporting the candidacy of ET-1 and its receptors for atopic asthma. A genetic association study was performed with variants of these three genes in both British (n = 300) and Japanese populations (n = 200). No significant association was found between variants of EDN1 and EDNRB genes, and atopic asthma in either population. However, variants of EDNRA gene showed a marginal association with atopy [odds = 0.39(95% CI: 0.17-0.89), p = 0.022, Pc = 0.066], especially with antigen specific IgE levels [odds = 0.31 (95% CI: 0.20-0.77), p = 0.006, Pc = 0.018] in the British population. These findings suggest that EDNRA is a major candidate locus for atopy on chromosome 4.

Topics: Antibody Specificity; Asthma; Chromosomes, Human, Pair 4; Endothelin-1; England; Female; Gene Frequency; Genetic Linkage; Genetic Variation; Genotype; Humans; Immunoglobulin E; Japan; Odds Ratio; Phenotype; Pregnancy; Protein Isoforms; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin

The aim of the study was to evaluate concentrations of atrial natriuretic peptide (ANP) and endothelin in blood serum of the patients with nonatopic bronchial asthma in the exacerbation phase and during non-symptomatic period. The study included 20 patients with nonatopic bronchial asthma (10 women and 10 men, mean age 34.2) treated in the Allergological Outpatient Clinic in Zabrze (Poland). A control group consisted of 5 healthy volunteers without atopy. The study consisted of evaluation of the ANP and endothelin in blood serum by radioimmunoassay and by functional respiratory tests. It was shown that ANP concentrations during bronchial asthma exacerbation were two times lower than in the same group examined in the remission phase (7.8-13.7 pmol/ml, p < 0.05). At the time of bronchospastic symptoms occurrence, the concentrations of endothelin were statistically significant and higher than in the non-symptomatic group (11.6-6.9 pmol/ml, p < 0.05). In the examined group the reverse proportion relation between concentrations of the studied peptides in blood serum was observed r = -0.56, p < 0.05 according to Spearman test.

Topics: Acute Disease; Adolescent; Adult; Analysis of Variance; Asthma; Atrial Natriuretic Factor; Endothelin-1; Female; Humans; Male; Middle Aged

That endothelin-1(ET-1) plays a mediator role in asthma is consistent with reports of ET-1-induced potentiation of cholinergic nerve-mediated contraction in airways from various animal species. This study examined the effect of ET-1 on cholinergic contractions in human isolated bronchus. Macroscopically nondiseased human bronchial tissue was obtained from 23 patients with respiratory tumours. An electrical field stimulation (EFS) frequency that produced one third of the contraction at 30 Hz (EFS30) was estimated. The effect of ET-1 on these EFS-evoked contractions was assessed. EFS-evoked contractions were frequency-dependent and abolished by either atropine or tetrodotoxin. Thus, EFS-induced contractions were mediated by acetylcholine from cholinergic nerves. ET-1 (3 nM) potentiated EFS-evoked contractions by 10+/-2% EFS30 (p<0.05) without any significant effect on contractions induced by exogenous acetylcholine. Neither the ET(A) receptor-selective antagonist BQ-123 (3 microM) nor the ET(B) receptor-selective antagonist BQ-788 (10 microM) alone significantly altered ET-1-induced potentiation of EFS-evoked contractions. However, in the combined presence of both BQ-123 and BQ-788, ET-1-induced potentiation of EFS-evoked contractions was abolished. Thus, prejunctional endothelinA and endothelinB receptors appear to mediate endothelin-1-induced potentiation of electrical field stimulation-evoked cholinergic contractions in human bronchus. This suggests another potentially important mechanism through which endothelin-1 could increase bronchial tone in asthma.

Topics: Adult; Airway Resistance; Asthma; Bronchi; Bronchoconstriction; Cholinergic Fibers; Culture Techniques; Endothelin-1; Female; Humans; Male; Middle Aged

To investigate the effects of relative imbalance between endothlin-1 (ET-1) and nitric oxide (NO) on pathogenesis of the ascaris-induced asthma in dogs.. Allergy induced asthma in dogs was established by inhaling ascaris antigen via an ultrasonic neblizer. At first, effects of ET-1 on respiratory system resistance (Rrs) and compliance (Crs) were studied in asthmatic dogs. Then, the roles of ET-1 and NO in regulating airway hyperresponsiveness (BHR) of asthma were investigated. Finally, effects of ET-1 on airway smooth muscle proliferating were observed.. After intravenous injection of ET-1, there was a significant maximal increase in Rrs with (14.33 +/- 0.53) mm Hg.L-1.s-1 in normal dogs and (30.75 +/- 3.38) mm Hg.L-1.s-1 (P < 0.05) in asthmatic dogs. Also, there was a significant maximal decrease in Crs with (24.9 +/- 1.2) L/mm Hg in normal dogs and (14.8 +/- 0.9) L/mm Hg (P < 0.05) in asthmatic dogs. The dose-dependent bronchoconstriction in dogs was induced by three different doses of ET-1 (0.25, 0.5, 1.0 microgram/kg). ET-1 dose-response curve was significantly shifted upward by L-NMMA (P < 0.05). This effect was inhibited by L-arg (P < 0.05). Histological studies showed that ET-1 can stimulate airway smooth muscle proliferating and thickening after one week of ET-1 (4.0 micrograms/kg) i.v. administration.. ET-1 might be involved in BHR that may be associated with immediate asthma response (IAR) in asthmatic dogs. ET-1 may be important for airway remodeling. The relative imbalance between ET-1 and NO may contribute to pathogenesis of asthma.

Topics: Animals; Arginine; Ascaris; Asthma; Disease Models, Animal; Dogs; Endothelin-1; Enzyme Inhibitors; Female; Infusions, Intravenous; Male; Muscle, Smooth, Vascular; Nitric Oxide; omega-N-Methylarginine

Erythromycin and its fourteen-member macrolide analogues have attracted attention for their efficacy in bronchial asthma. However, their mechanisms of action remain unclear. We evaluated the effects of the macrolide antibiotics on endothelin-1 (ET-1) expression in normal and transformed human bronchial epithelial cells, one of the sources of this potent bronchoconstrictor important in the pathogenesis of asthma. Human bronchial epithelial cells were obtained from the resected bronchi, and the effect of several antimicrobial and antiasthmatic drugs on the production and messenger ribonucleic acid (mRNA) levels of ET-1 was evaluated. Bronchoepithelial cells were also isolated from the mucosa of asthmatic patients under fibreoptic bronchoscopy, and the modulating effects of the drugs were studied. Erythromycin and clarithromycin uniquely suppressed mRNA levels as well as the release of ET- at therapeutic and non-cytotoxic concentrations (percentage inhibition of ET-1 protein release: 26.4+/-5.22% and 31.2+/-7.45%, respectively, at 10(-6) M). Furthermore, erythromycin and clarithromycin inhibited ET-1 expression in bronchoepithelial cells from patients with chronic, stable asthma. A glucocorticosteroid, dexamethasone, also inhibited ET-1 expression. In contrast, theophylline, salbutamol and FK506 had no effect on ET-1 production. Our findings demonstrated that these fourteen-member macrolide antibiotics had an inhibitory effect on endothelin-1 expression in human bronchial epithelial cells. Moreover, this new mode of action may have some relevance to their clinical efficacy in bronchial asthma.

Topics: Adult; Aged; Anti-Bacterial Agents; Asthma; Bronchi; Cell Line, Transformed; Clarithromycin; Culture Techniques; Cytokines; Endothelin-1; Epithelial Cells; Erythromycin; Female; Gene Expression; Humans; Male; Middle Aged; RNA, Messenger

Respiratory syncytial virus (RSV) infection causes and exacerbates asthma, yet the mechanism by which RSV triggers asthma is poorly understood. Herein, an in vitro model of RSV infection was established using HEp-2 and BEAS-2B bronchial epithelial cell lines, and the expression of 5-lipoxygenase (5-LO), and endothelin-1 (ET-1) was examined. RSV infection increased the expression of 5-LO mRNA and protein in both cell lines, as detected by RT-PCR and western blot analysis, respectively. The levels of leukotrienes also increased in the supernatants of RSV infected cells. Furthermore, RSV infection increased the expression of ET-1 mRNA and protein following RSV infection in a time-dependent manner. It is concluded that RSV infection upregulates the expression of ET-1 and 5-LO in the epithelial cells leading to the production of leukotrienes, which may mediate the consequent exacerbation of asthma.

Topics: Arachidonate 5-Lipoxygenase; Arachidonic Acid; Asthma; Bronchi; Cell Line; Endothelin-1; Epithelial Cells; Humans; Leukotrienes; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; RNA, Messenger; Up-Regulation

Recently, we have shown a substantial increase in the endothelin-1 (ET-1) concentration in bronchoalveolar fluid (BALF) during an experimental eosinophilic airway inflammation. Moreover, we observed a significant inhibition of the inflammatory response after treatment with an endothelin receptor antagonist. This indicates that ET-1 may have proinflammatory properties and play a key role in eosinophilic inflammations, such as bronchial asthma. Accordingly, we hypothesized that the synthesis and release of ET-1 precedes the inflammatory response, and that the bronchial epithelium is the site of ET-1 synthesis in the lungs. An eosinophilic airway inflammation was induced by intratracheal Sephadex instillation in rats, and the animals were evaluated after 15 min, 30 min, 1, 2, 3, 6, 12, and 48 h. The ET-1 mRNA synthesis, assessed by Northern and slot blot analyses, was significantly increased 15 min after Sephadex challenge, peaking at 30 min with a 4.7-fold increase, before any signs of inflammation in the BALF could be observed. The increased synthesis was mainly located to the bronchial epithelium and macrophages at sites of inflammation as determined by in situ hybridization. A significant increase in tissue ET-1 was observed 3 h after provocation, and the recruitment of eosinophils followed a substantial release of ET-1 peptide in BALF peaking at 24 h with a 13-fold increase. Therefore, the rapid ET-1 mRNA synthesis and the considerable increase in the level of ET-1 indicate that this peptide plays an important role in the initiation of an eosinophilic airway inflammation.

Topics: Animals; Asthma; Blotting, Northern; Bronchoalveolar Lavage Fluid; Cell Movement; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Eosinophils; Epithelium; Follow-Up Studies; In Situ Hybridization; Inflammation Mediators; Macrophages; Male; Pulmonary Eosinophilia; Rats; Rats, Wistar; RNA, Messenger

An increasing number of studies have been performed to address a possible role for endothelin-1 (ET-1) as a significant mediator in asthma. However, the effects of subthreshold concentrations of ET-1, which cannot elicit bronchial smooth muscle contraction itself, in asthma has yet to be determined. This study determined these effects of ET-1 on capsaicin-induced bronchoconstriction in anaesthetized guinea-pigs. Aerosolized ET-1 administered at doses of 10(-9) M and higher induced a dose-dependent increase in pulmonary resistance, but ET-1 at 10(-10) M did not have any bronchoconstrictive effect. However, this subthreshold concentration of ET-1 potentiated capsaicin-induced bronchoconstriction. In addition, the potentiation of capsaicin-induced bronchoconstriction by this subthreshold concentration of ET-1 was completely abolished by BQ788 (ET(B) receptor antagonist), but not BQ123 (ET(A) receptor antagonists). Immunoreactive substance P (SP) levels in bronchoalveolar lavage fluid after capsaicin administration were significantly higher than those after solvent administration. However, ET-1 alone did not significantly stimulate immunoreactive SP release and ET-1 (10(-10) M) did not potentiate capsaicin-induced immunoreactive SP release. In contrast, ET-1 (10(-10) M) potentiated exogenous neurokinin A- and SP-induced bronchoconstriction. These findings suggest that a subthreshold concentration of endothelin-1 does not potentiate the tachykinin release induced by capsaicin but the airway smooth muscle contraction through endothelin-B receptors.

Topics: Aerosols; Airway Resistance; Anesthesia; Animals; Asthma; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Capsaicin; Dose-Response Relationship, Drug; Endothelin Receptor Antagonists; Endothelin-1; Guinea Pigs; Male; Neurokinin A; Oligopeptides; Peptides, Cyclic; Piperidines; Substance P

To investigate the expressions of endothelin-1(ET-1) and endothelin converting enzyme (ECE) mRNA in bronchial mucosal biopsis from asthmatics, and the effect of inhaled-corticosteroids on the expressions of ET-1 and ECE genes.. The expressions of ET-1 and ECEmRNA in bronchial mucosal tissue were evaluated by reverse transcription DNA polymerase chain reaction (RT-PCR); With fibro bronchoscopy, the naked-eye inflammatory severity and inflammatory score of bronchial mucoses were recorded.. (1) The expression level of ET-1 mRNA was 0.86 +/- 0.06 in non-steroids-treated group and 0.14 +/- 0.06 in control non-asthmatic group. The expression of ECE mRNA in non-steroid group was 0.31 +/- 0.04, and 0.30 +/- 0.05 in control group, P = 0.238. (2) The ET-1 and ECE mRNA expressions were 0.22 +/- 0.01 and 0.16 +/- 0.01 respectively in steroid treated group. (3) The naked-eye bronchial mucosal inflammatory score was 6.0 +/- 1.9 in non-steroids treated group, moreover, the expression of ET-1 mRNA was positively correlated with the score (r = 0.78, P < 0.05).. There was markedly higher ET-1 mRNA expression in the bronchial mucosa in asthmatics, but the ECE mRNA expression was unchanged significantly; Inhaled corticosteroids obviously inhibited both ET-1 mRNA and ECE mRNA expressions in bronchial mucosa, which may be one of the anti-inflammatory mechanisms of inhaled-corticosteroid in management of bronchial asthma.

Topics: Adult; Anti-Asthmatic Agents; Aspartic Acid Endopeptidases; Asthma; Beclomethasone; Endothelin-1; Endothelin-Converting Enzymes; Female; Humans; Male; Metalloendopeptidases; RNA, Messenger

To investigate the role of the ET-1, TNF-alpha and oxidative radicals of MDA and SOD in the pathogenesis of asthma and the effect of the nitric oxide synthase inhibitor, L-NAME to above factors.. ET-1 was detected by the radio-immunoassay and TNF-alpha was detected by ELISA, SOD and MDA were detected by using thiobarbituric acid method.. The contents of ET-1, TNF(and MDA in the serum of the asthmatic patients and in the serum and lung tissue of asthma models of guinea pigs were significantly increased, in the contrast, the content of SOD was decreased compared with those in the controls(P < 0.01). All the changes in the serum and in the lung tissues of the asthma models of guinea pigs returned to the levels of the controls by dexamethasone inhalation or L-NAME by intraperitoneal injection.. ET-1, TNF alpha and the oxidative radicals and NO may play important roles in the pathogenesis of asthma, L-NAME, which is similar to the dexathamethsone, may either decrease the content of NO or decrease the content of ET-1, TNF alpha and oxidative radicals in asthma.

Topics: Adult; Animals; Asthma; Endothelin-1; Female; Guinea Pigs; Humans; Male; Malondialdehyde; Middle Aged; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Ovalbumin; Random Allocation; Superoxide Dismutase; Tumor Necrosis Factor-alpha

There is evidence that tumour necrosis factor alpha (TNF alpha) may be an important mediator in initiating asthmatic airway inflammation. It has been proposed that endothelin-1 (ET-1) is involved in bronchoconstriction and airway remodelling in asthma. It is not known, however, if there is any interaction between TNF alpha and ET in perpetuating airway inflammation in asthma.. The present study aimed to determine the activities of ET-1 and TNF alpha in ovalbumin-sensitized guinea pigs and their roles in the development of airway inflammation.. Twelve guinea pigs were sensitized by ovalbumin injection and aerosol inhalation. ET-1 levels were measured in both bronchoalveolar lavage fluid (BALF) and plasma by 125-labelled endothelin-1 (ET-1) radioimmunoassay. The TNF alpha activity released from alveolar macrophage (AM) in BALF was estimated by ELISA. Cultured bovine airway smooth muscle cells (BASMCs) were treated with TNF alpha (1000 units/5 x 10(4) cells) for different times. ET-1 levels in harvested medium from these cells were measured by radioimmunoassay. Cultured human fetal lung fibroblasts (HFLFs) were incubated with ET-1 (10(-8) approximately 10(-6)M), then 3HTdR incorporation to these cells and cell counting were performed. The effects of ET-1 stimulation on the granulocyte macrophage colony stimulating factor (GM-CSF) gene expression in HFLFs were estimated by using RT-PCR method.. ET-1 levels in both plasma and BALF were significantly higher in ovalbumin-sensitized guinea-pigs compared with those in controls (422.27 +/- 175.0 pg/mL vs 277.311 +/- 88.0 pg/mL, P < 0.05, 81.22 +/- 16.15 vs 49.81 +/- 12.64 pg/mL, P < 0.05) while TNF alpha activity was also significantly increased in the OVA-sensitized group compared with that in the control group (6010 +/- 1900 pg/mL vs 2810 +/- 450 pg/mL, P < 0.05). The ET-1 level in harvested medium of BASMCs rose significantly in 12 h in the TNF-alpha treated group (from < 5 pg/mL to 53.72 +/- 14.3 pg/mL, P < 0.001), and remained at a similar level for 24 h in the TNF alpha treated group. It was shown that ET-1 not only stimulated cell proliferation but also induced GM-CSF mRNA expression in HFLFs.. ET-1 levels in both plasma and BALF and TNF alpha release from macrophage are increased significantly in ovalbumin-sensitized guinea-pigs. TNF alpha stimulates ET-1 secretion from cultured BASMCsw; ET-1 accelerates cell proliferation and induces GM-CSF mRNA expression in the human fetal lung fibroblast.

Topics: Administration, Inhalation; Animals; Asthma; Bronchi; Bronchoalveolar Lavage Fluid; Cells, Cultured; Endothelin-1; Fibroblasts; Gene Expression; Granulocyte-Macrophage Colony-Stimulating Factor; Guinea Pigs; Inflammation; Macrophages, Alveolar; Male; Ovalbumin; Plasma; Tumor Necrosis Factor-alpha

Endothelin-1 (ET-1) is a potent bronchoconstrictor which may have a role in the pathogenesis of asthma. The levels of ET-1 in saliva, induced sputum, and plasma from asthmatic and non-asthmatic subjects were compared.. Sputum induction was performed on 28 asthmatic subjects and nine normal volunteers. ET-1 levels were measured in plasma, saliva, and sputum samples and reversed phase high performance liquid chromatography (RP-HPLC) was performed on saliva and sputum samples.. ET-1 was present in the following order of concentration in both normal and asthmatic subjects: saliva > sputum > plasma (saliva, median 30.1 and 23.9 pg/ ml, respectively; sputum, median 15.5 and 11.2 pg/ml; plasma, median 3.1 and 3.6 pg/ ml). There were no differences between asthmatic and normal subjects in the levels of ET-1 in each fluid. The levels of ET-1 in asthmatic subjects were not influenced by whether or not they were taking inhaled steroids. RP-HPLC of sputum and saliva confirmed the presence of ET-1 in these fluids.. Levels of ET-1 can be measured in saliva and sputum obtained by sputum induction in asthmatic and healthy subjects and, although no difference was found in basal levels of ET-1 in sputum, saliva and plasma between normal subjects and asthmatics without bronchoconstriction, it is apparent that ET-1 is produced or released locally within the respiratory tract in concentrations higher than those in plasma.

Topics: Adult; Asthma; Chromatography, High Pressure Liquid; Endothelin-1; Humans; Saliva; Specimen Handling; Sputum

Endothelin-1 may contribute to bronchial smooth muscle constriction and airway remodelling in asthma, where bronchial epithelial cells represent an important source of this peptide. We report here that asthmatic bronchial epithelial cells exposed to allergens in vitro induce the differentiation of airway fibroblasts into myofibroblasts, and that they do so through a granulocyte/macrophage colony-stimulating factor-mediated upregulation of endothelin-1 production. By this mechanism bronchial epithelial cells may participate in the genesis of bronchial subepithelial fibrosis, a process which contributes to airway narrowing in asthma.

Topics: Actins; Allergens; Asthma; Biomarkers; Bronchi; Cell Differentiation; Cells, Cultured; Culture Media; Endothelin-1; Fibroblasts; Humans; Immunohistochemistry; Recombinant Proteins

We have previously demonstrated that human bronchial smooth muscle cells possess specific binding sites for the potent bronchoconstrictive peptide endothelin 1 and that primary cultures of human bronchial epithelial cells constitutively produce an endothelin-like material that binds to smooth muscle cell receptors with a kinetic ability analogous to that shown by the authentic peptide. To evaluate the potential role of airway epithelium-derived endothelin in the pathogenesis of asthma, we have examined here the expression of endothelin in the bronchial epithelial cells of 6 patients with symptomatic asthma and reversible airflow obstruction. The epithelial cells of 5 normal volunteers and 5 patients with chronic bronchitis and airflow obstruction unaffected by bronchodilators were tested as controls. The bronchial epithelial cells of all the asthmatic patients expressed preproendothelin 1 mRNA, as assessed by in situ hybridization, and released high amounts of mature and biologically active endothelin during a 48-h period of incubation (radioimmunoassay). By contrast, the epithelial cells from normal donors did not contain preproendothelin 1 transcripts, and the endothelin-like material in their supernatants was invariably below the detection limit of the assay. Only a few cells from 2 patients with chronic bronchitis expressed preproendothelin mRNA and endothelin immunoreactivity. When hydrocortisone (10(-6)M) was added to the culture medium of asthmatic bronchial epithelial cells for 48 h, the release of immunoreactive endothelin significantly decreased (p < 0.025), but the numbers of cells expressing preproendothelin 1 mRNA did not change to the same extent.

Topics: Adrenal Cortex Hormones; Adult; Asthma; Biopsy; Bronchi; Bronchoscopy; Endothelin-1; Endothelins; Epithelium; Evaluation Studies as Topic; Female; Forced Expiratory Volume; Humans; Male; Peak Expiratory Flow Rate; Protein Precursors