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1.
Am J Physiol Lung Cell Mol Physiol ; 318(5): L943-L952, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32233794

RESUMO

Transient receptor potential ankyrin-1 (TRPA1) is a ligand-gated cation channel that responds to endogenous and exogenous irritants. TRPA1 is expressed on multiple cell types throughout the lungs, but previous studies have primarily focused on TRPA1 stimulation of airway sensory nerves. We sought to understand the integrated physiological airway response to TRPA1 stimulation. The TRPA1 agonists allyl isothiocyanate (AITC) and cinnamaldehyde (CINN) were tested in sedated, mechanically ventilated guinea pigs in vivo. Reproducible bronchoconstrictions were induced by electrical stimulation of the vagus nerves. Animals were then treated with intravenous AITC or CINN. AITC and CINN were also tested on isolated guinea pig and mouse tracheas and postmortem human trachealis muscle strips in an organ bath. Tissues were contracted with methacholine, histamine, or potassium chloride and then treated with AITC or CINN. Some airways were pretreated with TRPA1 antagonists, the cyclooxygenase inhibitor indomethacin, the EP2 receptor antagonist PF 04418948, or tetrodotoxin. AITC and CINN blocked vagally mediated bronchoconstriction in guinea pigs. Pretreatment with indomethacin completely abolished the airway response to TRPA1 agonists. Similarly, AITC and CINN dose-dependently relaxed precontracted guinea pig, mouse, and human airways in the organ bath. AITC- and CINN-induced airway relaxation required TRPA1, prostaglandins, and PGE2 receptor activation. TRPA1-induced airway relaxation did not require epithelium or tetrodotoxin-sensitive nerves. Finally, AITC blocked airway hyperreactivity in two animal models of allergic asthma. These data demonstrate that stimulation of TRPA1 causes bronchodilation of intact airways and suggest that the TRPA1 pathway is a potential pharmacological target for bronchodilation.


Assuntos
Dinoprostona/metabolismo , Músculo Liso/metabolismo , Canal de Cátion TRPA1/genética , Traqueia/metabolismo , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Broncoconstrição/efeitos dos fármacos , Estimulação Elétrica , Regulação da Expressão Gênica , Cobaias , Histamina/farmacologia , Humanos , Indometacina/farmacologia , Isotiocianatos/farmacologia , Masculino , Cloreto de Metacolina/farmacologia , Camundongos , Músculo Liso/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Cloreto de Potássio/farmacologia , Prostaglandina-Endoperóxido Sintases/genética , Prostaglandina-Endoperóxido Sintases/metabolismo , Respiração Artificial , Transdução de Sinais , Canal de Cátion TRPA1/agonistas , Canal de Cátion TRPA1/antagonistas & inibidores , Canal de Cátion TRPA1/metabolismo , Tetrodotoxina/farmacologia , Traqueia/efeitos dos fármacos , Nervo Vago/fisiologia
2.
Am J Respir Cell Mol Biol ; 63(1): 57-66, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32182104

RESUMO

It is well known that the prevalence of asthma is higher in athletes, including Olympic athletes, than in the general population. In this study, we analyzed the mechanism of exercise-induced bronchoconstriction by using animal models of athlete asthma. Mice were made to exercise on a treadmill for a total duration of 1 week, 3 weeks, or 5 weeks. We analyzed airway responsiveness, BAL fluid, lung homogenates, and tissue histology for each period. In mice that were treated (i.e., the treatment model), treatments were administered from the fourth to the fifth week. We also collected induced sputum from human athletes with asthma and analyzed the supernatants. Airway responsiveness to methacholine was enhanced with repeated exercise stimulation, although the cell composition in BAL fluid did not change. Exercise induced hypertrophy of airway smooth muscle and subepithelial collagen deposition. Cysteinyl-leukotriene (Cys-LT) levels were significantly increased with exercise duration. Montelukast treatment significantly reduced airway hyperresponsiveness (AHR) and airway remodeling. Expression of PLA2G4 (phospholipase A2 group IV) and leukotriene C4 synthase in the airway epithelium was upregulated in the exercise model, and inhibition of PLA2 ameliorated AHR and airway remodeling, with associated lower levels of Cys-LTs. The levels of Cys-LTs in sputum from athletes did not differ between those with and without sputum eosinophilia. These data suggest that AHR and airway remodeling were caused by repeated and strenuous exercise. Cys-LTs from the airway epithelium, but not inflammatory cells, may play an important role in this mouse model.


Assuntos
Remodelação das Vias Aéreas/fisiologia , Broncoconstrição/fisiologia , Cisteína/metabolismo , Fosfolipases A2 do Grupo II/metabolismo , Leucotrienos/metabolismo , Condicionamento Físico Animal/fisiologia , Acetatos/farmacologia , Remodelação das Vias Aéreas/efeitos dos fármacos , Animais , Asma/tratamento farmacológico , Asma/metabolismo , Hiper-Reatividade Brônquica/tratamento farmacológico , Hiper-Reatividade Brônquica/metabolismo , Broncoconstrição/efeitos dos fármacos , Feminino , Leucotrienos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Quinolinas/farmacologia , Hipersensibilidade Respiratória/tratamento farmacológico , Hipersensibilidade Respiratória/metabolismo
3.
Int J Vitam Nutr Res ; 90(1-2): 141-150, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30789805

RESUMO

Anti-inflammatory effect of Curcuma longa (C. longa) was shown previously. In the present study, the effect of the plant on tracheal responsiveness and lung pathological features in ovalbumin-sensitized rats was evaluated. Six groups of rats including control (C), ovalbumin (OVA)-sensitized (S), S groups treated with C. longa (CL; 0.75, 1.50, and 3.00 mg/ml equal to 150, 300 and 600 mg/kg/day) and dexamethasone (D; 1.25 µg/ml) were studied (n=8 in each group). The extract of C. longa and dexamethasone were administered with daily drinking water of animals during sensitization period (for 21 days). Following the treatment period, tracheal responsiveness to methacholine and ovalbumin and lung pathological features was investigated. Tracheal responsiveness to methacholine and OVA and lung pathological scores were increased in group S compared to controls (p<0.01 to p<0.001); however, these parameters in groups treated with dexamethasone and two higher concentrations of C. longa were significantly decreased compared to group S (p<0.05 to p<0.001). Tracheal responsiveness to methacholine was decreased from 50 to 400% due to the extract treatment. All concentrations of C. longa significantly decreased interstitial fibrosis compared to group S (p<0.05 to p<0.001). Treatment with the extract resulted to improvement of pathological changes from 20 to 70%. These results showed a preventive effect for C. longa extract on tracheal responsiveness and lung pathological insults in sensitized rats which were similar or even more than those of dexamethasone at used concentrations.


Assuntos
Curcuma , Pulmão/efeitos dos fármacos , Cloreto de Metacolina/farmacologia , Extratos Vegetais , Traqueia/efeitos dos fármacos , Animais , Pulmão/patologia , Cloreto de Metacolina/química , Ovalbumina , Extratos Vegetais/farmacologia , Ratos , Traqueia/patologia
4.
Am J Physiol Lung Cell Mol Physiol ; 318(2): L287-L295, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31747299

RESUMO

TMEM16A (anoctamin 1) is an important calcium-activated chloride channel in airway smooth muscle (ASM). We have previously shown that TMEM16A antagonists such as benzbromarone relax ASM and have proposed TMEM16A antagonists as novel therapies for asthma treatment. However, TMEM16A is also expressed on airway epithelium, and TMEM16A agonists are being investigated as novel therapies for cystic fibrosis. There are theoretical concerns that agonism of TMEM16A on ASM could lead to bronchospasm, making them detrimental as airway therapeutics. The TMEM16A agonist Eact induced a significant contraction of human ASM and guinea pig tracheal rings in an ex vivo organ bath model. Pretreatment with two different TMEM16A antagonists, benzbromarone or T16Ainh-A01, completely attenuated these Eact-induced contractions. Pretreatment with Eact alone augmented the maximum acetylcholine contraction. Pretreatment of A/J mice in vivo with nebulized Eact caused an augmentation of methacholine-induced increases in airway resistance measured by the forced oscillatory technique (flexiVent). Pretreatment with the TMEM16A antagonist benzbromarone significantly attenuated methacholine-induced increases in airway resistance. In in vitro cellular studies, TMEM16A was found to be expressed more abundantly in ASM compared with epithelial cells in culture (8-fold higher in ASM). Eact caused an increase in intracellular calcium in human ASM cells that was completely attenuated by pretreatment with benzbromarone. Eact acutely depolarized the plasma membrane potential of ASM cells, which was attenuated by benzbromarone or nifedipine. The TMEM16A agonist Eact modulates ASM contraction in both ex vivo and in vivo models, suggesting that agonism of TMEM16A may lead to clinically relevant bronchospasm.


Assuntos
Anoctamina-1/agonistas , Anoctamina-1/metabolismo , Pulmão/metabolismo , Tono Muscular , Músculo Liso/metabolismo , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/metabolismo , Acetilcolina/farmacologia , Animais , Anoctamina-1/genética , Hiper-Reatividade Brônquica/fisiopatologia , Broncoconstrição/efeitos dos fármacos , Cálcio/metabolismo , Células Cultivadas , Cobaias , Humanos , Fosfatos de Inositol/biossíntese , Cloreto de Metacolina/farmacologia , Contração Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , Proteínas de Neoplasias/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Exp Physiol ; 104(12): 1801-1807, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31602716

RESUMO

NEW FINDINGS: What is the central question of this study? Does ageing augment muscarinic, nicotinic and/or ATP-mediated cutaneous vasodilatation in women? What is the main finding and its importance? Ageing augments nicotinic and ATP-induced, but not muscarinic, cutaneous vasodilatation in women. This will stimulate future studies assessing the pathophysiological significance of the augmented microvascular responsiveness in older women compared to their young counterparts. ABSTRACT: We previously reported that ageing attenuates adenosine triphosphate (ATP)-induced, but not muscarinic and nicotinic, cutaneous vasodilatation in men, and that ageing may augment cutaneous vascular responses in women. In the present study, we evaluated the hypothesis that ageing augments muscarinic, nicotinic and/or ATP-mediated cutaneous vasodilatation in healthy women. In 11 young (23 ± 5 years) and 11 older (60 ± 8 years) women, cutaneous vascular conductance was evaluated at three forearm skin sites that were perfused with (1) methacholine (muscarinic receptor agonist, 5 doses: 0.0125, 0.25, 5, 100, 2000 mm), (2) nicotine (nicotinic receptor agonist, 5 doses: 1.2, 3.6, 11, 33, 100 mm), or (3) ATP (purinergic receptor agonist, 5 doses: 0.03, 0.3, 3, 30, 300 mm). Each agonist was administered for 25 min per dose. Methacholine-induced increases in cutaneous vascular conductance were not different between groups at all doses (all P > 0.05). However, a nicotine-induced elevation in cutaneous vascular conductance at the lowest concentration (1.2 mm) was greater in older vs. young women (43 ± 15 vs. 26 ± 10%max, P = 0.04). ATP-induced increases in cutaneous vascular conductance at moderate and high doses (3 and 30 mm) were also greater in older relative to young women (3 mm, 44 ± 11 vs. 28 ± 10%max, P = 0.02; 30 mm, 83 ± 14 vs. 64 ± 17%max, P = 0.05). Therefore, ageing augments nicotinic and ATP-induced, but not muscarinic, cutaneous vasodilatation in women.


Assuntos
Trifosfato de Adenosina/farmacologia , Envelhecimento/efeitos dos fármacos , Antebraço/fisiologia , Agonistas Muscarínicos/farmacologia , Nicotina/farmacologia , Pele/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Adolescente , Adulto , Idoso , Envelhecimento/fisiologia , Relação Dose-Resposta a Droga , Feminino , Antebraço/irrigação sanguínea , Humanos , Fluxometria por Laser-Doppler/métodos , Cloreto de Metacolina/farmacologia , Microcirculação/efeitos dos fármacos , Microcirculação/fisiologia , Pessoa de Meia-Idade , Pele/irrigação sanguínea , Vasodilatação/fisiologia , Adulto Jovem
6.
J Appl Physiol (1985) ; 127(6): 1528-1538, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31545157

RESUMO

The shortening of airway smooth muscle (ASM) is greatly affected by time. This is because stimuli affecting ASM shortening, such as bronchoactive molecules or the strain inflicted by breathing maneuvers, not only alter quick biochemical processes regulating contraction but also slower processes that allow ASM to adapt to an ever-changing length. Little attention has been given to the effect of time on ASM shortening. The present study investigates the effect of changing the time interval between simulated deep inspirations (DIs) on ASM shortening and its responsiveness to simulated DIs. Excised tracheal strips from sheep were mounted in organ baths and either activated with methacholine or relaxed with isoproterenol. They were then subjected to simulated DIs by imposing swings in distending stress, emulating a transmural pressure from 5 to 30 cmH2O. The simulated DIs were intercalated by 2, 5, 10, or 30 min. In between simulated DIs, the distending stress was either fixed or oscillating to simulate tidal breathing. The results show that although shortening was increased by prolonging the interval between simulated DIs, the bronchodilator effect of simulated DIs (i.e., the elongation of the strip post- vs. pre-DI) was not affected, and the rate of re-shortening post-simulated DIs was decreased. As the frequency with which DIs are taken increases upon bronchoconstriction, our results may be relevant to typical alterations observed in asthma, such as an increased rate of re-narrowing post-DI.NEW & NOTEWORTHY The frequency with which patients with asthma take deep inspirations (DIs) increases during bronchoconstriction. This in vitro study investigated the effect of changing the time interval between simulated DIs on airway smooth muscle shortening. The results demonstrated that decreasing the interval between simulated DIs not only decreases shortening, which may be protective against excessive airway narrowing, but also increases the rate of re-shortening post-simulated DIs, which may contribute to the increased rate of re-narrowing post-DI observed in asthma.


Assuntos
Resistência das Vias Respiratórias/fisiologia , Brônquios/fisiologia , Broncoconstrição/fisiologia , Músculo Liso/fisiologia , Ovinos/fisiologia , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Asma/fisiopatologia , Brônquios/efeitos dos fármacos , Broncoconstrição/efeitos dos fármacos , Broncoconstritores/farmacologia , Broncodilatadores/farmacologia , Feminino , Inalação/efeitos dos fármacos , Isoproterenol/farmacologia , Masculino , Cloreto de Metacolina/farmacologia , Músculo Liso/efeitos dos fármacos , Traqueia/efeitos dos fármacos , Traqueia/fisiopatologia
7.
Thorax ; 74(11): 1055-1062, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31534032

RESUMO

BACKGROUND: Acute pollutant-related lung function changes among children varies across pollutants and lag periods. We examined whether short-term air pollutant fluctuations were related to daily lung function among a panel of children and whether these effects are modified by airway hyperresponsiveness, location and asthma severity. METHODS: Students from randomly selected grade 4 classrooms at seven primary schools in Durban, participated, together with asthmatic children from grades 3-6 (n=423). The schools were from high pollutant exposed communities (south) and compared with schools from communities with lower levels of pollution (north), with similar socioeconomic profiles. Interviews, spirometry and methacholine challenge testing were conducted. Bihourly lung function measurements were performed over a 3-week period in four phases. During all schooldays, students blew into their personal digital monitors every 1.5-2 hours. Nitrogen dioxide (NO2), nitrogen oxide (NO), sulphur dioxide and particulate matter (<10 µm diameter) (PM10) were measured at each school. Generalised estimating equations assessed lag effects, using single-pollutant (single or distributed lags) models. RESULTS: FEV1 declines ranged from 13 to 18 mL per unit increase in IQR for NO and 14-23 mL for NO2. Among the 5-day average models, a 20 mL and 30 mL greater drop in FEV1 per IQR for NO2 and NO, respectively, among those with airway hyperresponsiveness compared with those without. Effects were seen among those with normal airways. CONCLUSIONS: This first panel study in sub-Saharan Africa, showed significant declines in lung function, in response to NO and NO2 with effects modified by airway hyperresponsiveness or persistent asthma.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Asma/fisiopatologia , Pulmão/fisiopatologia , Poluentes Atmosféricos/análise , Animais , Broncoconstritores/farmacologia , Criança , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/efeitos dos fármacos , Masculino , Cloreto de Metacolina/farmacologia , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/toxicidade , Óxidos de Nitrogênio/análise , Óxidos de Nitrogênio/toxicidade , Material Particulado/análise , Material Particulado/toxicidade , Instituições Acadêmicas , Índice de Gravidade de Doença , África do Sul , Espirometria , Dióxido de Enxofre/análise , Dióxido de Enxofre/toxicidade , Fatores de Tempo
8.
PLoS One ; 14(9): e0221899, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31513609

RESUMO

INTRODUCTION: Genome-Wide Association Studies suggest glutathione S transferase C terminal domain (GSTCD) may play a role in development of Chronic Obstructive Pulmonary Disease. We aimed to define the potential role of GSTCD in airway inflammation and contraction using precision cut lung slice (PCLS) from wild-type (GSTCD+/+) and GSTCD knockout mice (GSTCD-/-). METHODS: PCLS from age and gender matched GSTCD+/+ and GSTCD-/- mice were prepared using a microtome. Contraction was studied after applying either a single dose of Methacholine (Mch) (1 µM) or different doses of Mch (0.001 to 100 µM). Each slice was then treated with lipopolysaccharide (LPS) or vehicle (PBS) for 24 hours. PCLS contraction in the same airway was repeated before and after stimulation. Levels of TNFα production was also measured. RESULTS: There were no differences in contraction of PCLS from GSTCD+/+ and GSTCD-/- mice in response to Mch (EC50 of GSTCD+/+ vs GSTCD-/- animals: 100.0±20.7 vs 107.7±24.5 nM, p = 0.855, n = 6 animals/group). However, after LPS treatment, there was a 31.6% reduction in contraction in the GSTCD-/- group (p = 0.023, n = 6 animals). There was no significant difference between PBS and LPS treatment groups in GSTCD+/+ animals. We observed a significant increase in TNFα production induced by LPS in GSTCD-/- lung slices compared to the GSTCD+/+ LPS treated slices. CONCLUSION: GSTCD knockout mice showed an increased responsiveness to LPS (as determined by TNFα production) that was accompanied by a reduced contraction of small airways in PCLS. These data highlight an unrecognised potential function of GSTCD in mediating inflammatory signals that affect airway responses.


Assuntos
Bronquíolos/fisiologia , Glutationa Transferase/genética , Lipopolissacarídeos/efeitos adversos , Cloreto de Metacolina/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Bronquíolos/efeitos dos fármacos , Bronquíolos/imunologia , Modelos Animais de Doenças , Feminino , Técnicas de Inativação de Genes , Masculino , Camundongos , Contração Muscular/efeitos dos fármacos , Regulação para Cima
9.
Respir Med ; 156: 53-57, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31434037

RESUMO

BACKGROUND: Inhaled corticosteroids (ICS) decrease airway inflammation and airway hyperresponsiveness (AHR). Previous studies have generally investigated the effect of ICS on methacholine-induced AHR following weeks or months of medium to high dose treatment. PURPOSE: The short-term effects of once-daily fluticasone furoate (FF) 100 mcg on methacholine-induced AHR and airway inflammation were examined over the course of one week. METHODS: Eleven mild asthmatics completed this randomized, double-blind crossover study. Once-daily FF (100 mcg) and identical appearing placebo Ellipta® inhalers were given for 7 days with a 2-week washout. Methacholine challenges were performed before and 24 h after the first, third and seventh doses. Fractional exhaled nitric oxide (FeNO) was measured initially and at 7 days. RESULTS: FF significantly (p = 0.0009-0.0078) increased methacholine PD20 (provocative dose causing 20% fall in forced expiratory volume in 1 s) at all times. Doubling dose shifts (95% CI) were 1.23 (0.60-1.86), 1.17 (0.68-1.67) and 1.44 (0.93-1.94) after the first, third and seventh dose respectively. FeNO (geometric mean, 95% CI) decreased significantly (p = 0.0049) following FF treatment from 37.9 ppb (23.7-60.5) initially to 22.9 ppb (14.8-35.5) at 7 days. Placebo did not affect methacholine PD20 or FeNO. CONCLUSION: Single-dose FF 100 mcg decreased methacholine AHR at 24 h without significant further improvement with continued daily use over 7 days. The inhibition in AHR after one week of daily dosing coincided with a significant decrease in FeNO at 7 days. Contrary to past assumptions, the ICS FF appears to rapidly reduce AHR to methacholine.


Assuntos
Androstadienos/administração & dosagem , Androstadienos/farmacologia , Asma/tratamento farmacológico , Asma/fisiopatologia , Broncoconstrição/efeitos dos fármacos , Cloreto de Metacolina/farmacologia , Humanos , Índice de Gravidade de Doença , Fatores de Tempo
10.
Respir Res ; 20(1): 165, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31340811

RESUMO

BACKGROUND: Complement factor C5 can either aggravate or attenuate the T-helper type 2 (TH2) immune response and airway hyperresponsiveness (AHR) in murine models of allergic asthma. The effect of C5 during the effector phase of allergen-induced asthma is ill-defined. OBJECTIVES: We aimed to determine the effect of C5 blockade during the effector phase on the pulmonary TH2 response and AHR in a house dust mite (HDM) driven murine asthma model. METHODS: BALB/c mice were sensitized and challenged repeatedly with HDM via the airways to induce allergic lung inflammation. Sensitized mice received twice weekly injections with a blocking anti-C5 or control antibody 24 h before the first challenge. RESULTS: HDM challenge in sensitized mice resulted in elevated C5a levels in bronchoalveolar lavage fluid. Anti-C5 administered to sensitized mice prior to the first HDM challenge prevented this rise in C5a, but did not influence the influx of eosinophils or neutrophils. While anti-C5 did not impact the recruitment of CD4 T cells upon HDM challenge, it reduced the proportion of TH2 cells recruited to the airways, attenuated IL-4 release by regional lymph nodes restimulated with HDM ex vivo and mitigated the plasma IgE response. Anti-C5 did not affect innate lymphoid cell (ILC) proliferation or group 2 ILC (ILC2) differentiation. Anti-C5 attenuated HDM induced AHR in the absence of an effect on lung histopathology, mucus production or vascular leak. CONCLUSIONS: Generation of C5a during the effector phase of HDM induced allergic lung inflammation contributes to TH2 cell differentiation and AHR without impacting ILC2 cells.


Assuntos
Asma/imunologia , Complemento C5a/antagonistas & inibidores , Complemento C5a/imunologia , Imunidade Inata/imunologia , Pyroglyphidae/imunologia , Células Th2/imunologia , Animais , Asma/induzido quimicamente , Asma/prevenção & controle , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Imunidade Inata/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Células Th2/efeitos dos fármacos
11.
J Aerosol Med Pulm Drug Deliv ; 32(6): 352-363, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31259673

RESUMO

Background: Asthma is widely treated using inhaled corticosteroid/long-acting beta agonist (LABA) combinations, for example, fluticasone propionate/salmeterol (FPS) dry powder inhaler, marketed as Advair® Diskus®. Some regulators require generics to demonstrate local (lung) therapeutic equivalence (LTE) for each component of the FPS reference, ideally with a dose-response within the approved FPS dose range. We sought to develop a methacholine challenge (MeCh) LTE methodology for assessing the LABA (salmeterol) component of FPS. Methods: Forty-six patients with asthma received single doses of albuterol (active control; 90 or 180 µg), FPS (100/50 or 200/100 µg), and placebo on 5 separate study days. Spirometry and MeCh were performed 1, 6, and 10 hours after study drug inhalation. Primary endpoint was provocative concentration of methacholine producing a 20% fall in forced expiratory volume in 1 second (PC20). Study entry required screening PC20 ≤8 mg/mL, with a greater than fourfold increase (and PC20 ≤128 mg/mL) after 180 µg albuterol. Results: Both albuterol (90 and 180 µg) and FPS (100/50 and 200/100 µg) significantly increased PC20 compared with placebo (sustained 6 and 10 hours postdose with FPS but not albuterol). The dose-response slopes (95% confidence interval) estimated 1 hour after treatment were 0.374 (-0.068 to 0.815) and 0.310 (-0.135 to 0.754) between low and high doses of albuterol and FPS, respectively, both nonsignificant. Slopes were shallower than those available in the literature for albuterol and formoterol, but similar to those for salmeterol. Conclusions: These data confirm that the bronchoprotective effect of FPS lasts longer than that of albuterol. The shallow dose-response slope we observed for albuterol is contrary to previous reports, probably due to the measurement of PC20 beginning at 1 hour postdose. The results suggest that use of MeCh to assess LTE for salmeterol formulations may be more difficult to accomplish than it is for albuterol and formoterol products.


Assuntos
Antiasmáticos/administração & dosagem , Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Combinação Fluticasona-Salmeterol/administração & dosagem , Administração por Inalação , Adolescente , Adulto , Albuterol/administração & dosagem , Albuterol/farmacologia , Antiasmáticos/farmacologia , Testes de Provocação Brônquica , Broncodilatadores/farmacologia , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Inaladores de Pó Seco , Feminino , Combinação Fluticasona-Salmeterol/farmacologia , Volume Expiratório Forçado , Humanos , Masculino , Cloreto de Metacolina/administração & dosagem , Cloreto de Metacolina/farmacologia , Pessoa de Meia-Idade , Equivalência Terapêutica , Adulto Jovem
12.
Respir Med Res ; 76: 4-9, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31254946

RESUMO

INTRODUCTION: The impact of fractional exhaled nitric oxide (FENO) on the management of chronic cough (CC) is still inconclusive. The aim of the present study was to assess whether FENO is a good tool to predict the response to inhaled corticosteroids (ICS) in patients with CC. METHODS: Patients, referred for investigation of CC, had a FENO measurement determined as part of their first-line assessment. A methacholine test was performed as part of a second-line assessement. Patients were assigned to two groups according to their FENO values: a high FENO level group (â°¥25 ppb) and a normal FENO level group (<25 ppb). RESULTS: One hundred patients were included in the study. High FENO levels were found in 25 patients (25%). The proportion of patients who responded to ICS was significantly greater in the high FENO group compared to the normal FENO level group (86.4% vs 46.3%, P<0.05). FENO is a good tool to predict ICS response in patients with high FENO levels but a response to ICS cannot be ruled out in patients with normal FENO levels. In patients with normal FENO values, a methacholine test could be an interesting tool for a second-line assessment. Among the 13 patients with a positive methacholine test result, 11 responded to ICS whilst 2 did not. Of the patients with a negative methacholine test result, 3 responded to ICS whilst 13 did not. CONCLUSION: FENO may be a more reliable predictor of ICS response when used as part of a multi-step assessment procedure.


Assuntos
Corticosteroides/administração & dosagem , Tosse/diagnóstico , Tosse/tratamento farmacológico , Expiração/fisiologia , Óxido Nítrico/análise , Administração por Inalação , Adulto , Idoso , Testes Respiratórios/métodos , Testes de Provocação Brônquica , Doença Crônica , Tosse/metabolismo , Tosse/patologia , Monitoramento de Medicamentos/métodos , Feminino , França , Humanos , Masculino , Cloreto de Metacolina/farmacologia , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
13.
Eur Respir J ; 54(2)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31109984

RESUMO

Neutrophilic inflammation in asthma is associated with interleukin (IL)-17A, corticosteroid-insensitivity and bronchodilator-induced forced expiratory volume in 1 s (FEV1) reversibility. IL-17A synergises with tumour necrosis factor (TNF)-α in the production of the neutrophil chemokine CXCL-8 by primary bronchial epithelial cells (PBECs).We hypothesised that local neutrophilic inflammation in asthma correlates with IL-17A and TNF-α-induced CXCL-8 production by PBECs from asthma patients.PBECs from most asthma patients displayed an exaggerated CXCL-8 production in response to TNF-α and IL-17A, but not to TNF-α alone, and which was also insensitive to corticosteroids. This hyperresponsiveness of PBECs strongly correlated with CXCL-8 levels and neutrophil numbers in bronchoalveolar lavage from the corresponding patients, but not with that of eosinophils. In addition, this hyperresponsiveness also correlated with bronchodilator-induced FEV1 % reversibility. At the molecular level, epithelial hyperresponsiveness was associated with failure of the translational repressor T-cell internal antigen-1 related protein (TiAR) to translocate to the cytoplasm to halt CXCL-8 production, as confirmed by TiAR knockdown. This is in line with the finding that hyperresponsive PBECs also produced enhanced levels of other inflammatory mediators.Hyperresponsive PBECs in asthma patients may underlie neutrophilic and corticosteroid-insensitive inflammation and a reduced FEV1, irrespective of eosinophilic inflammation. Normalising cytoplasmic translocation of TiAR is a potential therapeutic target in neutrophilic, corticosteroid-insensitive asthma.


Assuntos
Asma/fisiopatologia , Epitélio/metabolismo , Interleucina-17/metabolismo , Neutrófilos/metabolismo , Adolescente , Corticosteroides/uso terapêutico , Adulto , Idoso , Albuterol/farmacologia , Asma/patologia , Brônquios/metabolismo , Brônquios/patologia , Hiper-Reatividade Brônquica/metabolismo , Lavagem Broncoalveolar , Linhagem Celular Tumoral , Citoplasma/metabolismo , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Volume Expiratório Forçado , Humanos , Inflamação , Interleucina-8/metabolismo , Pulmão/patologia , Masculino , Cloreto de Metacolina/farmacologia , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Testes de Função Respiratória , Fumar , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
14.
Am J Physiol Lung Cell Mol Physiol ; 317(1): L99-L108, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31042080

RESUMO

Reactive airway diseases are significant sources of pulmonary morbidity in neonatal and pediatric patients. Supplemental oxygen exposure in premature infants contributes to airway diseases such as asthma and promotes development of airway remodeling, characterized by increased airway smooth muscle (ASM) mass and extracellular matrix (ECM) deposition. Decreased plasma membrane caveolin-1 (CAV1) expression has been implicated in airway disease and may contribute to airway remodeling and hyperreactivity. Here, we investigated the impact of clinically relevant moderate hyperoxia (50% O2) on airway remodeling and caveolar protein expression in a neonatal mouse model. Within 12 h of birth, litters of B6129SF2J mice were randomized to room air (RA) or 50% hyperoxia exposure for 7 days with or without caveolin-1 scaffolding domain peptide (CSD; caveolin-1 mimic; 10 µl, 0.25 mM daily via intraperitoneal injection) followed by 14 days of recovery in normoxia. Moderate hyperoxia significantly increased airway reactivity and decreased pulmonary compliance at 3 wk. Histologic assessment demonstrated airway wall thickening and increased ASM mass following hyperoxia. RNA from isolated ASM demonstrated significant decreases in CAV1 and cavin-1 in hyperoxia-exposed animals while cavin-3 was increased. Supplementation with intraperitoneal CSD mitigated both the physiologic and histologic changes observed with hyperoxia. Overall, these data show that moderate hyperoxia is detrimental to developing airway and may predispose to airway reactivity and remodeling. Loss of CAV1 is one mechanism through which hyperoxia produces these deleterious effects. Supplementation of CAV1 using CSD or similar analogs may represent a new therapeutic avenue for blunting hyperoxia-induced pulmonary damage in neonates.


Assuntos
Anti-Inflamatórios/farmacologia , Hiper-Reatividade Brônquica/tratamento farmacológico , Caveolina 1/farmacologia , Hiperóxia/tratamento farmacológico , Pulmão/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Remodelação das Vias Aéreas/efeitos dos fármacos , Remodelação das Vias Aéreas/imunologia , Animais , Animais Recém-Nascidos , Hiper-Reatividade Brônquica/etiologia , Hiper-Reatividade Brônquica/genética , Hiper-Reatividade Brônquica/imunologia , Broncoconstritores/farmacologia , Caveolina 1/genética , Caveolina 1/imunologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Hiperóxia/etiologia , Hiperóxia/genética , Hiperóxia/imunologia , Injeções Intraperitoneais , Pulmão/imunologia , Pulmão/patologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Cloreto de Metacolina/farmacologia , Camundongos , Oxigênio/efeitos adversos , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia , Transdução de Sinais
15.
Toxicol Sci ; 169(2): 499-510, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30825310

RESUMO

Sex differences clearly exist in incidence, susceptibility, and severity of airway disease and in pulmonary responses to air pollutants such as ozone (O3). Prior rodent O3 exposure studies demonstrate sex-related differences in the expression of lung inflammatory mediators and signaling. However, whether or not sex modifies O3-induced airway physiologic responses remains less explored. To address this, we exposed 8- to 10-week-old male and female C57BL/6 mice to either 1 or 2 ppm O3 or filtered air (FA) for 3 h. At 12, 24, 48, and 72 h following exposure, we assessed airway hyperresponsiveness to methacholine (MCh), bronchoalveolar lavage fluid cellularity, cytokines and total protein/albumin, serum progesterone, and whole lung immune cells by flow cytometry. Male mice generated consistent airway hyperresponsiveness to MCh at all time points following exposure. Alternatively, females had less consistent airway physiologic responses to MCh, which were more variable between individual experiments and did not correlate with serum progesterone levels. Bronchoalveolar lavage fluid total cells peaked at 12 h and were persistently elevated through 72 h. At 48 h, bronchoalveolar lavage cells were greater in females versus males. Bronchoalveolar lavage fluid cytokines and total protein/albumin increased following O3 exposure without sex differences. Flow cytometry of whole lung tissue identified dynamic O3-induced immune cell changes also independent of sex. Our results indicate sex differences in acute O3-induced airway physiology responses and airspace influx without significant difference in other injury and inflammation measures. This study highlights the importance of considering sex as a biological variable in acute O3-induced airway physiology responses.


Assuntos
Ozônio/toxicidade , Hipersensibilidade Respiratória/induzido quimicamente , Doença Aguda , Animais , Citocinas/análise , Feminino , Imunofenotipagem , Masculino , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Progesterona/sangue , Caracteres Sexuais
16.
Iran J Allergy Asthma Immunol ; 18(1): 48-61, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30848573

RESUMO

Epidemiological and clinical studies have demonstrated a close association between obesity and asthma. The current study investigated the effect of high-fat diet on tracheal responsiveness to methacholine and insulin resistance in ovalbumin (OVA) sensitized male and female rats. The rats were divided into eight groups (n=6 per group): female with the normal diet (F+ND), male with the normal diet (M+ND), female OVA-sensitized with the normal diet (F+SND), male OVA-sensitized with the normal diet (M+SND), female with high-fat diet (F+HFD), male with high-fat diet (M+HFD), female OVA-sensitized with high-fat diet (F+SHFD), and male OVA-sensitized with high-fat diet (M+SHFD). All rats were fed for 8 weeks with high-fat diet or standard pelts, and for another 4 weeks, they were sensitized with OVA or saline. At the end of the study, the tracheal responsiveness to methacholine, serum insulin, and blood glucose levels was measured. Also, insulin resistance indexes were determined. OVA-sensitization and diet-induced obesity caused the curve of methacholine concentration response to shifting to the left. In addition, results indicated that the EC50 (the effective concentration of methacholine generating 50% of peak response) in F+SHFD rats was statistically lower than M+SHFD group (p<0.05). Moreover, insulin resistance was higher in the F+SHFD than the M+SHFD group (p<0.001). These results suggest that insulin resistance and metabolic syndrome may be involved in the pathogenesis of obesity associated with OVA-sensitized rats condition, especially in female animals.


Assuntos
Asma/fisiopatologia , Broncoconstritores/farmacologia , Dieta Hiperlipídica , Resistência à Insulina , Cloreto de Metacolina/farmacologia , Obesidade/fisiopatologia , Traqueia/efeitos dos fármacos , Alérgenos , Animais , Glicemia/análise , Modelos Animais de Doenças , Feminino , Insulina/sangue , Masculino , Ovalbumina , Ratos Wistar , Traqueia/fisiopatologia
17.
Sci Rep ; 9(1): 279, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670753

RESUMO

We have previously shown that high fat diet (HFD) for 2 weeks increases airway hyperresponsiveness (AHR) to methacholine challenge in C57BL/6J mice in association with an increase in IL-1ß levels in lung tissue. We hypothesize that obesity increases AHR via the IL-1ß mechanism, which can be prevented by caloric restriction and IL-1ß blockade. In this study, we fed C57BL/6J mice for 8 weeks with several hypercaloric diets, including HFD, HFD supplemented with fructose, high trans-fat diet (HTFD) supplemented with fructose, either ad libitum or restricting their food intake to match body weight to the mice on a chow diet (CD). We also assessed the effect of the IL-1ß receptor blocker anakinra. All mice showed the same total respiratory resistance at baseline. All obese mice showed higher AHR at 30 mg/ml of methacholine compared to CD and food restricted groups, regardless of the diet. Obese mice showed significant increases in lung IL-1 ß mRNA expression, but not the protein, compared to CD and food restricted mice. Anakinra abolished an increase in AHR. We conclude that obesity leads to the airway hyperresponsiveness preventable by caloric restriction and IL-1ß blockade.


Assuntos
Restrição Calórica , Dieta Hiperlipídica , Hipersensibilidade Respiratória/prevenção & controle , Animais , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Interleucina-1beta/antagonistas & inibidores , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Obesidade
18.
Respir Physiol Neurobiol ; 259: 136-142, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30217723

RESUMO

A certain amount of time is required to achieve a maximal contraction from airway smooth muscle (ASM) and stretches of substantial magnitude, such as the ones imparted by deep inspirations (DIs), interfere with contraction. The duration of ASM contraction without interference may thus affect its shortening, its mechanical response to DIs and the overall toll it exerts on the respiratory system. In this study, the effect of changing the interval between DIs on the dynamics of ASM was examined in vitro. Isolated bronchi derived from guinea pigs were held isotonically and stimulated to both contract and relax, in a randomized order, in response to 10-5 M of methacholine and 10-6 M of isoproterenol, respectively. Interference to ASM was inflicted after 2, 5, 10 and 30 min in a randomized order, by imposing a stretch that simulated a DI. The shortening before the stretch, the stiffness before and during the stretch, the post-stretch elongation of ASM and the ensuing re-shortening were measured. These experiments were also performed in the presence of simulated tidal breathing achieved through force fluctuations. The results demonstrate that, with or without force fluctuations, increasing the interval between simulated DIs increased shortening and post-stretch elongation, but not stiffness and re-shortening. These time-dependent effects were not observed when ASM was held in the relaxed state. These findings may help understand to which extent ASM shortening and the regulatory effect of DI are affected by changing the interval between DIs. The potential consequences of these findings on airway narrowing are also discussed.


Assuntos
Resistência das Vias Respiratórias/fisiologia , Brônquios/citologia , Inalação/fisiologia , Contração Muscular/fisiologia , Músculo Liso/fisiologia , Dinâmica não Linear , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Broncoconstritores/farmacologia , Broncodilatadores/farmacologia , Feminino , Cobaias , Técnicas In Vitro , Inalação/efeitos dos fármacos , Isoproterenol/farmacologia , Cloreto de Metacolina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Estimulação Física , Fatores de Tempo
19.
Respir Physiol Neurobiol ; 259: 156-161, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30367990

RESUMO

To clarify the potential of dopamine to alter airway tone in the presence of different bronchoconstrictor stimuli, changes in airway function following dopamine administrations were characterized when the bronchial tone was elevated by stimulating the histaminic or cholinergic pathway. Airway resistance, tissue damping and tissue elastance were measured in anesthetized mechanically ventilated rabbits under baseline conditions, during steady-state bronchoconstriction induced by methacholine or histamine, and following intravenous dopamine (5 and 15 µg/kg/min). Bronchoconstriction induced by methacholine and histamine was significantly ameliorated by dopamine (14.8 ± 2.9% and 14.9 ± 2.9%; p < 0.05 for both), with no difference between the mode of stimuli. Dopamine had no effect on the tissue mechanics. These findings indicate that dopamine relaxes the elevated airway smooth muscle tone without affecting the lung periphery, and this effect is independent of the mode of constrictor stimuli. This profile of dopamine suggests its ability to treat effectively cholinergic and histaminergic bronchoconstriction, besides its positive inotropic effects on the myocardial contractility.


Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Broncoconstrição/efeitos dos fármacos , Dopamina/farmacologia , Histamina/farmacologia , Cloreto de Metacolina/farmacologia , Mecânica Respiratória/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Agonistas Muscarínicos/farmacologia , Músculo Liso/efeitos dos fármacos , Coelhos
20.
Am J Respir Cell Mol Biol ; 60(4): 434-444, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30359078

RESUMO

Cystic fibrosis (CF) is an autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator gene. Many patients with CF have asthma-like symptoms and airway hyperresponsiveness, which are potentially associated with altered airway smooth muscle (ASM) contractility. Our goal in this study was to assess the contractility of the CF intrapulmonary ASM. ASM strips were dissected from human control and CF intrapulmonary airways, and assessed for methacholine-induced shortening velocity, maximal force, and stress. We also assessed isoproterenol responses in maximally methacholine-contracted ASM. ASM strips were then incubated for 16 hours with IL-13 and measurements were repeated. Myosin light chain kinase (MLCK) expression was assessed by Western blotting. Airways were immunostained for morphometry. ASM mass was increased in CF airways, which likely contributes to airway hyperresponsiveness. Although ASM contractile properties were not intrinsically different between patients with CF and control subjects, CF ASM responded differently in the presence of the inflammatory mediator IL-13, showing impairment in ß-adrenergic-induced relaxation. Indeed, the percentage of relaxation measured at maximal isoproterenol concentrations in the CF ASM was significantly lower after incubation with IL-13 (46.0% ± 6.7% relaxation) than without IL-13 (74.0% ± 7.7% relaxation, P = 0.018). It was also significantly lower than that observed in control ASM incubated with IL-13 (68.8% ± 4.9% relaxation, P = 0.048) and without IL-13 (82.4% ± 9.9%, P = 0.0035). CF ASM incubated with IL-13 also expressed greater levels of MLCK. Thus, our data suggest that the combination of an increase in ASM mass, increased MLCK expression, and inflammation-induced ß-adrenergic hyporesponsiveness may contribute to airway dysfunction in CF.


Assuntos
Asma/patologia , Fibrose Cística/patologia , Contração Muscular/fisiologia , Músculo Liso/patologia , Hipersensibilidade Respiratória/patologia , Adulto , Broncoconstritores/farmacologia , Broncodilatadores/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Feminino , Humanos , Interleucina-13/farmacologia , Isoproterenol/farmacologia , Masculino , Cloreto de Metacolina/farmacologia , Pessoa de Meia-Idade , Quinase de Cadeia Leve de Miosina/biossíntese , Sistema Respiratório/patologia , Adulto Jovem
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