RESUMO
RATIONAL: Acute lung injury (ALI) is a common complication after intestinal ischemia and reperfusion (I/R) injury that can lead to acute respiratory distress syndrome (ARDS). We have previously demonstrated that females are protected against lung damage induced by intestinal I/R through an estrogen mediated mechanism. OBJECTIVES: To investigate the effect of obesity on ALI induced by intestinal I/R in female mice. METHODS: C57Bl/6 female mice were fed with a standard low-fat diet (SD) or a high-fat diet (HFD) for 9 weeks. Intestinal I/R injury was induced by a 45â¯min occlusion of the mesenteric artery followed by 2 and 24â¯h of reperfusion. RESULTS: Significant increase in lung myeloperoxidase expression (MPO) and neutrophil numbers of SD and HFD mice occurred at 2â¯h and 24â¯h of reperfusion. Furthermore, HFD mice presented a significant increase in lung eosinophil peroxidase (EPO) expression and eosinophil numbers compared to SD mice. Lung wet/dry weight ratio was significantly greater in HFD mice at 2 and 24â¯h of reperfusion, accompanied by a significant increase in the expression of inducible NO in the lung tissue and a significant decrease in arterial oxygen saturation at 24â¯h of reperfusion relative to SD mice. CONCLUSION: Obesity predisposes female mice to increased pulmonary oedema and deterioration in gas exchange, which is accompanied by an increase in iNOS expression in the lung.
Assuntos
Lesão Pulmonar Aguda/etiologia , Obesidade/complicações , Edema Pulmonar/etiologia , Traumatismo por Reperfusão/complicações , Lesão Pulmonar Aguda/fisiopatologia , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Intestinos/irrigação sanguínea , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Peroxidase/metabolismo , Troca Gasosa Pulmonar/fisiologia , Fatores SexuaisRESUMO
The small GTPase Rac is required for neutrophil recruitment during inflammation, but its guanine-nucleotide exchange factor (GEF) activators seem dispensable for this process, which led us to investigate the possibility of cooperation between Rac-GEF families. Thioglycollate-induced neutrophil recruitment into the peritoneum was more severely impaired in P-Rex1(-/-) Vav1(-/-) (P1V1) or P-Rex1(-/-) Vav3(-/-) (P1V3) mice than in P-Rex null or Vav null mice, suggesting cooperation between P-Rex and Vav Rac-GEFs in this process. Neutrophil transmigration and airway infiltration were all but lost in P1V1 and P1V3 mice during lipopolysaccharide (LPS)-induced pulmonary inflammation, with altered intercellular adhesion molecule 1-dependent slow neutrophil rolling and strongly reduced L- and E-selectin-dependent adhesion in airway postcapillary venules. Analysis of adhesion molecule expression, neutrophil adhesion, spreading, and migration suggested that these defects were only partially neutrophil-intrinsic and were not obviously involving vascular endothelial cells. Instead, P1V1 and P1V3 platelets recapitulated the impairment of LPS-induced intravascular neutrophil adhesion and recruitment, showing P-Rex and Vav expression in platelets to be crucial. Similarly, during ovalbumin-induced allergic inflammation, pulmonary recruitment of P1V1 and P1V3 eosinophils, monocytes, and lymphocytes was compromised in a platelet-dependent manner, and airway inflammation was essentially abolished, resulting in improved airway responsiveness. Therefore, platelet P-Rex and Vav family Rac-GEFs play important proinflammatory roles in leukocyte recruitment.
Assuntos
Plaquetas/metabolismo , Quimiotaxia de Leucócito/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Inflamação/genética , Inflamação/imunologia , Proteínas Proto-Oncogênicas c-vav/genética , Doença Aguda , Animais , Adesão Celular/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Lipopolissacarídeos , Camundongos , Camundongos Knockout , Infiltração de Neutrófilos/genética , Pneumonia/genética , Pneumonia/imunologia , Proteínas Proto-Oncogênicas c-vav/metabolismoRESUMO
Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (ß2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs.
Assuntos
Antitussígenos/uso terapêutico , Tosse/induzido quimicamente , Tosse/tratamento farmacológico , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Aminopiridinas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Benzamidas/farmacologia , Broncoconstrição/efeitos dos fármacos , Broncodilatadores/uso terapêutico , Capsaicina , Ácido Cítrico , Ciclopropanos/farmacologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Cobaias , Masculino , Infiltração de Neutrófilos/efeitos dos fármacos , Propilenoglicóis/farmacologia , Coelhos , Canais de Potencial de Receptor Transitório/metabolismoRESUMO
BACKGROUND: Cough is a common presenting symptom in patients with idiopathic interstitial pneumonia (IIP); it is often disabling, and lacks effective treatment. Studies in animals suggest that carcainium chloride, a quaternary derivative of the local anesthetic lidocaine, is able to inhibit experimentally induced cough by a mechanism of action distinct from that of lidocaine. OBJECTIVE: To determine the effectiveness of aerosolised carcainium chloride (VRP700) in controlling cough in patients with IIP. METHODS: Eight female patients (mean age 71 years) with IIP were investigated in a double blind, randomised, placebo controlled crossover, adaptive contingency study design (EudraCT Number 2010-021350-19). The study consisted of a screening visit to assess the eligibility of patients, and two separated (48-72 h) study days. On the two study days, patients were randomised to receive either nebulized VRP700 (1.0 mg/kg) on the first study visit followed by nebulised placebo (sodium chloride 0.9%) on the second visit, or placebo on the first visit followed by VRP700 on the second visit. The primary endpoint was cough frequency over a 4-h assessment period; secondary endpoints were subjective cough-related level of discomfort as assessed by a visual analogue scale (VAS) and the subjective response to treatment as assessed by a quality of life question. Safety (ECG, spirometry, urine and blood tests) and adverse events occurring during the trial were also investigated. RESULTS: In all patients both VRP700 and placebo decreased cough frequency; however, mean decreases in cough frequency after treatment with VRP700 were significantly (P < 0.001) higher than with placebo. Similarly, mean reductions in VAS score were significantly (P < 0.001) higher after treatment with VRP 700 compared with placebo. All but one patient indicated that they felt better after receiving VRP700. No adverse events were reported during the study, nor were any changes in ECG variables, spirometry, urine and blood tests noted. CONCLUSION: The results of this exploratory study indicate that nebulised VRP700 improved cough and quality of life in hospitalised IIP patients with no significant side effects. A larger trial is warranted to assess these promising results.
Assuntos
Anestésicos Locais/uso terapêutico , Tosse/tratamento farmacológico , Pneumonias Intersticiais Idiopáticas/tratamento farmacológico , Lidocaína/análogos & derivados , Administração por Inalação , Aerossóis , Idoso , Anestésicos Locais/administração & dosagem , Anestésicos Locais/efeitos adversos , Antitussígenos/administração & dosagem , Antitussígenos/efeitos adversos , Antitussígenos/uso terapêutico , Doença Crônica , Tosse/etiologia , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Pneumonias Intersticiais Idiopáticas/fisiopatologia , Lidocaína/administração & dosagem , Lidocaína/efeitos adversos , Lidocaína/uso terapêutico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Qualidade de VidaRESUMO
It is now recognized that certain polysaccharides can exhibit anti-inflammatory activity, including the glycosaminoglycan (GAG) heparin that is widely used as an anti-coagulant drug. However, it would be desirable to identify molecules that retain the anti-inflammatory actions of heparin, but that are devoid of significant anti-coagulant activity. In the present study we have identified a number of novel GAG and GAG-like polysaccharides (VRP327) from marine organisms, most of which were resistant to digestion by heparinase II and chondroitinase ABC. Fourier transform infra-red spectrum (FTIR) revealed species with variable degrees of sulphation and monosaccharide analysis revealed a range of sugar compounds, which in some cases included sugars not present in mammalian GAGs. (1)H NMR spectra of these species are consistent with the structures of complex polysaccharides. From an initial screening cascade to remove compounds having significant anti-coagulant activity and no overt cytotoxicity, we identified a high molecular weight oversulphated dermatan sulphate (VRP327) isolated from the tunicate Ascidiella aspersa which was fully characterised by NMR spectroscopy. This material was depolymerised to produce well characterized low molecular weight fractions which were demonstrated to be non-toxic, with low levels of anti-coagulant activity, and to have demonstrable anti-inflammatory activity assessed in several in vitro and in vivo models. The identification of low molecular weight polysaccharides having significant anti-inflammatory activity without significant anti-coagulant activity may provide novel templates for the development of a novel class of anti-inflammatory drugs.
Assuntos
Anti-Inflamatórios/isolamento & purificação , Glicosaminoglicanos/isolamento & purificação , Polissacarídeos/isolamento & purificação , Urocordados/metabolismo , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Anticoagulantes/farmacologia , Dermatan Sulfato/química , Dermatan Sulfato/isolamento & purificação , Dermatan Sulfato/farmacologia , Modelos Animais de Doenças , Glicosaminoglicanos/química , Glicosaminoglicanos/farmacologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular , Polissacarídeos/química , Polissacarídeos/farmacologiaRESUMO
Fucosylated chondroitin sulfate (fCS) extracted from the sea cucumber Holothuria forskali is composed of the following repeating trisaccharide unit: â 3)GalNAcß4,6S(1 â 4) [FucαX(1 â 3)]GlcAß(1 â, where X stands for different sulfation patterns of fucose (X = 3,4S (46%), 2,4S (39%), and 4S (15%)). As revealed by NMR and molecular dynamics simulations, the fCS repeating unit adopts a conformation similar to that of the Le(x) blood group determinant, bringing several sulfate groups into close proximity and creating large negative patches distributed along the helical skeleton of the CS backbone. This may explain the high affinity of fCS oligosaccharides for L- and P-selectins as determined by microarray binding of fCS oligosaccharides prepared by Cu(2+)-catalyzed Fenton-type and photochemical depolymerization. No binding to E-selectin was observed. fCS poly- and oligosaccharides display low cytotoxicity in vitro, inhibit human neutrophil elastase activity, and inhibit the migration of neutrophils through an endothelial cell layer in vitro. Although the polysaccharide showed some anti-coagulant activity, small oligosaccharide fCS fragments had much reduced anticoagulant properties, with activity mainly via heparin cofactor II. The fCS polysaccharides showed prekallikrein activation comparable with dextran sulfate, whereas the fCS oligosaccharides caused almost no effect. The H. forskali fCS oligosaccharides were also tested in a mouse peritoneal inflammation model, where they caused a reduction in neutrophil infiltration. Overall, the data presented support the action of fCS as an inhibitor of selectin interactions, which play vital roles in inflammation and metastasis progression. Future studies of fCS-selectin interaction using fCS fragments or their mimetics may open new avenues for therapeutic intervention.
Assuntos
Anti-Inflamatórios não Esteroides/química , Sulfatos de Condroitina/química , Doenças do Sistema Imunitário/tratamento farmacológico , Transtornos Leucocíticos/tratamento farmacológico , Peritonite/tratamento farmacológico , Proteínas Secretadas Inibidoras de Proteinases/química , Pepinos-do-Mar/química , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/metabolismo , Anti-Inflamatórios não Esteroides/farmacologia , Configuração de Carboidratos , Sulfatos de Condroitina/isolamento & purificação , Sulfatos de Condroitina/metabolismo , Sulfatos de Condroitina/farmacologia , Peróxido de Hidrogênio , Doenças do Sistema Imunitário/metabolismo , Doenças do Sistema Imunitário/patologia , Ferro , Selectina L/química , Selectina L/metabolismo , Transtornos Leucocíticos/metabolismo , Transtornos Leucocíticos/patologia , Elastase de Leucócito/antagonistas & inibidores , Elastase de Leucócito/metabolismo , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/patologia , Oxirredução , Selectina-P/química , Selectina-P/metabolismo , Peritonite/metabolismo , Peritonite/patologia , Proteínas Secretadas Inibidoras de Proteinases/isolamento & purificação , Proteínas Secretadas Inibidoras de Proteinases/metabolismo , Proteínas Secretadas Inibidoras de Proteinases/farmacologiaRESUMO
Cannabis has been demonstrated to have bronchodilator, anti-inflammatory, and antitussive activity in the airways, but information on the active cannabinoids, their receptors, and the mechanisms for these effects is limited. We compared the effects of Δ(9)-tetrahydrocannabinol, cannabidiol, cannabigerol, cannabichromene, cannabidiolic acid, and tetrahydrocannabivarin on contractions of the guinea pig-isolated trachea and bronchoconstriction induced by nerve stimulation or methacholine in anesthetized guinea pigs following exposure to saline or the proinflammatory cytokine, tumor necrosis factor α (TNF-α). CP55940 (2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl) cyclohexyl]-5-(2-methyloctan-2-yl)phenol), a synthetic cannabinoid agonist, was also investigated in vitro. The cannabinoids were also evaluated on TNF-α- and lipopolysaccharide-induced leukocyte infiltration into the lungs and citric acid-induced cough responses in guinea pigs. TNF-α, but not saline, augmented tracheal contractility and bronchoconstriction induced by nerve stimulation, but not methacholine. Δ(9)-Tetrahydrocannabinol and CP55940 reduced TNF-α-enhanced nerve-evoked contractions in vitro to the magnitude of saline-incubated trachea. This effect was antagonized by the cannabinoid 1 (CB(1)) and CB(2) receptor antagonists AM251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-caroxamide] and JTE907 [N-(1,3-benzodioxol-5-ylmethyl)-1,2-dihydro-7-methoxy-2-oxo-8-(pentyloxy)-3-quinolinecarboxamide], respectively. Tetrahydrocannabivarin partially inhibited the TNF-α-enhanced nerve-evoked contractions, whereas the other cannabinoids were without effect. The effect of cannabidiol and Δ(9)-tetrahydrocannabinol together did not differ from that of the latter alone. Only Δ(9)-tetrahydrocannabinol inhibited TNF-α-enhanced vagal-induced bronchoconstriction, neutrophil recruitment to the airways, and citric acid-induced cough responses. TNF-α potentiated contractions of airway smooth muscle in response to nerve stimulation by enhancing postganglionic acetylcholine release. Δ(9)-Tetrahydrocannabinol and CP55940 inhibited the TNF-α-enhanced acetylcholine release, and hence contraction and bronchoconstriction, through activation of presynaptic CB(1) and CB(2) receptors. The other cannabinoids did not influence cholinergic transmission, and only Δ(9)-THC demonstrated effects on airway hyper-responsiveness, anti-inflammatory activity, and antitussive activity in the airways.
Assuntos
Canabinoides/farmacologia , Tosse/prevenção & controle , Hipersensibilidade Respiratória/prevenção & controle , Sistema Respiratório/efeitos dos fármacos , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Broncoconstrição/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/farmacologia , Cannabis , Ácido Cítrico , Tosse/induzido quimicamente , Tosse/imunologia , Cicloexanóis/farmacologia , Cobaias , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/prevenção & controle , Contração Isométrica/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Masculino , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiopatologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/fisiopatologia , Sistema Respiratório/imunologia , Sistema Respiratório/fisiopatologia , Traqueia/efeitos dos fármacos , Traqueia/fisiopatologia , Fator de Necrose Tumoral alfaRESUMO
PURPOSE OF REVIEW: ß2-Agonists and muscarinic antagonists are widely used to treat asthma and chronic obstructive pulmonary disease (COPD), and a number of novel drug targets are being investigated for potential clinical utility. This review will summarize current developments in the field. RECENT FINDINGS: The clinical effectiveness of a number of once a day inhaled ß2-agonists and muscarinic antagonists is a major advance providing sustained bronchodilation in asthma and COPD. The identification of novel targets (e.g. bitter taste receptor TASR2), the demonstration of clinical effectiveness of others [e.g. phosphodiesterase (PDE)3/4] and exploring the potential of inverse agonists/biased agonists are evidence of continuing interest in the development of novel bronchodilators. SUMMARY: Novel long-acting ß2-agonists (e.g. indacaterol, vilanterol, olodaterol and carmoterol) and muscarinic antagonists (e.g. tiotropium, aclidinium, glycopyrronium and umeclidinium bromide) document sustained bronchodilation and their combination provides additional benefits over monotherapy. Not surprisingly, inhaled long-acting ß2-agonist and long-acting muscarinic antagonists remain the drugs of choice for maintenance bronchodilation. However, there is a continued interest in developing novel bronchodilators illustrated by the clinical effectiveness of long acting mixed PDE3/4 inhibitors, vasointestinal peptide adenylyl cyclase agonists and inverse agonists/biased agonists for the ß2-adrenoceptor, and the identification of intracellular (e.g. Rho kinase, exchange proteins activated by cyclic AMP) and cell surface (e.g. TAS2R, natriuretic peptide receptor) targets.
Assuntos
Asma/tratamento farmacológico , Broncodilatadores/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Broncodilatadores/administração & dosagem , Humanos , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/uso terapêutico , Resultado do TratamentoRESUMO
The phosphodiesterase (PDE) enzyme family hydrolyzes cAMP and cGMP, second messengers that regulate a variety of cellular processes, including airway smooth muscle (ASM) relaxation and the inhibition of inflammatory cells. We investigated the activity of RPL554 [9,10-dimethoxy-2(2,4,6-trimethylphenylimino)-3-(n-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one], a dual PDE3/PDE4 inhibitor that exhibits bifunctional activity for its effects on the tone of human isolated ASM and any potential synergistic interactions with muscarinic receptor antagonists or a ß2-agonist. We evaluated the influence of RPL554 on the contractile response induced by electrical field stimulation (EFS), acetylcholine (ACh), or histamine on human isolated bronchi. We also analyzed the potential synergistic effect of RPL554 in combination with atropine, glycopyrollate, or salbutamol by using the Berenbaum Bliss Independence (BI), or the dose equivalence methods. RPL554 inhibited the contraction induced by EFS [maximal effectiveness (Emax) 91.33 ± 3.37%, P < 0.001], relaxed bronchi precontracted with ACh (Emax 94.62 ± 2.63%, pD2 4.84 ± 0.12, P < 0.001), and abolished the contraction induced by histamine. Analysis of interactions indicated a weak synergism between RPL554 and salbutamol (interaction index: 0.25 ± 0.06; BI Δeffect: 0.29 ± 0.11; dose equivalence: no synergism) but significant synergism between RPL554 and atropine (interaction index: 0.09 ± 0.07; BI Δeffect: 0.54 ± 0.09; dose equivalence: synergism for low concentrations) or glycopyrrolate (ACh: BI Δeffect 0.46 ± 0.03, Berenbaum Δeffect 0.42 ± 0.02; histamine: BI Δeffect 0.46 ± 0.03, Berenbaum Δeffect 0.42 ± 0.03). This study demonstrates that RPL554 relaxes human bronchi and that it can interact with a muscarinic receptor antagonist to produce a synergistic inhibition of ASM tone. These results suggest that RPL554 may provide a novel treatment of airway diseases, either alone or in combination with antimuscarinic drugs.
Assuntos
Brônquios/efeitos dos fármacos , Isoquinolinas/farmacologia , Músculo Liso/efeitos dos fármacos , Inibidores da Fosfodiesterase 3/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Pirimidinonas/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Albuterol/farmacologia , Atropina/farmacologia , Sinergismo Farmacológico , Estimulação Elétrica , Feminino , Glicopirrolato/farmacologia , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Antagonistas Muscarínicos/farmacologia , Contração Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacosRESUMO
A novel wideband parametric baseband macromodeling technique for passive photonic devices and circuits is presented. It allows to efficiently estimate the baseband scattering representations of a linear, passive photonic system as a function of a set of design variables, such as geometrical layout or substrate features. The proposed technique relies on the interpolation of macromodels computed via a complex vector fitting (CVF) algorithm, by adopting a methodology based on amplitude and frequency scaling that preserves, by construction, the physical properties of the system, such as causality, stability and passivity. For a specified combination of the design parameters, a rational CVF model is derived that can be simulated by a wide range of ordinary differential equation (ODE) solvers or circuit simulators. Additionally, time-domain simulations using the computed model can be performed at arbitrary optical carrier frequencies, thus allowing for the simulation of multi-wavelength systems. Two application examples are presented to demonstrate the flexibility and advantages of the proposed method.
RESUMO
Chaperonin 60.1 from Mycobacterium tuberculosis suppressed allergic lung inflammation and bronchial hyperresponsiveness in mice by a mechanism that is yet to be clarified. To investigate the possible antiinflammatory mechanism(s) of action of Cpn60.1 in a model of allergic lung inflammation, ovalbumin (OVA)-allergic mice were pretreated with Cpn60.1 intranasally 20 minutes before each OVA aerosol challenge in a total of three treatments. Readouts were performed 24 hours after last challenge. Pretreatment with Cpn60.1 (1.0-0.001 µg) significantly inhibited the number of eosinophils in bronchoalveolar lavage fluid (OVA, 49.2 ± 12.3 versus Cpn60.1 [1 µg dose], 90.4 ± 2.3 × 10(4) cells/ml) and IL-5 release (OVA, 43 ± 8.5 versus Cpn60.1 [1 µg dose], 3 ± 11 pg/ml) but increased IL-12 levels (OVA, 50 ± 24 versus Cpn60.1 [1 µg dose], 103 ± 13 pg/ml). The effect of Cpn60.1 on cell recruitment and IL-5, but not IL-12, release was abolished in TLR-4 knockout mice. Intravital microscopy demonstrated that Cpn60.1 reduced chemokine-mediated leukocyte rolling and transmigration across the vessel wall (rolling cells: eotaxin, 11.7 ± 1.1 versus Cpn60.1 [1 µg dose], 2.8 ± 1 cells in 30 s). Similarly, Cpn60.1 reduced eotaxin-induced leukocyte migration in vitro (eotaxin, 17.3 ± 3.3 versus Cpn60.1 [0.1 µg dose], 3.3 ± 0.4 cells × 10(4)/ml). Immunostaining demonstrated that Cpn60.1 inhibits VCAM-1 and increases vascular endothelial-cadherin expression in lung vascular tissue, suggesting that the antiinflammatory effect of Cpn60.1 is partly mediated by altering the expression of adhesion molecules. This study shows that Cpn60.1 inhibits leukocyte diapedesis by a TLR-4 and an adhesion molecule-dependent mechanism in allergic inflammation in mice.
Assuntos
Chaperonina 60/farmacologia , Leucócitos/imunologia , Mycobacterium tuberculosis/imunologia , Pneumonia/imunologia , Animais , Anti-Inflamatórios , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/metabolismo , Líquido da Lavagem Broncoalveolar/imunologia , Moléculas de Adesão Celular/imunologia , Moléculas de Adesão Celular/metabolismo , Chaperonina 60/imunologia , Modelos Animais de Doenças , Eosinófilos/imunologia , Eosinófilos/metabolismo , Feminino , Interleucina-12/imunologia , Interleucina-12/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Leucócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mycobacterium tuberculosis/metabolismo , Ovalbumina/imunologia , Pneumonia/metabolismo , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismoRESUMO
OBJECTIVE: To investigate the involvement of transient receptor potential ankyrin 1 (TRPA1) in inflammatory hyperalgesia mediated by tumor necrosis factor α(TNFα) and joint inflammation. METHODS: Mechanical hyperalgesia was assessed in CD1 mice, mice lacking functional TRP vanilloid 1 (TRPV1-/-) or TRPA1 (TRPA1-/-), or respective wildtype (WT) mice. An automated von Frey system was used, following unilateral intraplantar injection of TNFα or intraarticular injection of Freund's complete adjuvant (CFA). Knee swelling and histologic changes were determined in mice treated with intraarticular injections of CFA. RESULTS: TNFα induced cyclooxygenase-independent bilateral mechanical hyperalgesia in CD1 mice. The selective TRPV1 receptor antagonist SB-366791 had no effect on mechanical hyperalgesia when it was coinjected with TNFα, but intrathecally administered SB- 366791 attenuated bilateral hyperalgesia, indicating the central but not peripheral involvement of TRPV1 receptors. A decrease in pain sensitivity was also observed in TRPV1-/- mice. Intraplantar coadministration of the TRPA1 receptor antagonist AP-18 with TNFα inhibited bilateral hyperalgesia. Intrathecal treatment with AP-18 also reduced TNFα-induced hyperalgesia. CFA-induced mechanical hyperalgesia in CD1 mice was attenuated by AP-18 (administered by intraarticular injection 22 hours after the administration of CFA). Furthermore, intraarticular CFAinduced ipsilateral mechanical hyperalgesia was maintained for 3 weeks in TRPA1 WT mice. In contrast, TRPA1-/- mice exhibited mechanical hyperalgesia for only 24 hours after receiving CFA. CONCLUSION: Evidence suggests that endogenous activation of peripheral TRPA1 receptors plays a critical role in the development of TNFα-induced mechanical hyperalgesia and in sustaining the mechanical hyperalgesia observed after intraaarticular injection of CFA. These results suggest that blockade of TRPA1 receptors may be beneficial in reducing the chronic pain associated with arthritis.
Assuntos
Artrite Experimental/imunologia , Hiperalgesia/imunologia , Canais de Cátion TRPV/imunologia , Canais de Potencial de Receptor Transitório/imunologia , Fator de Necrose Tumoral alfa/imunologia , Adjuvantes Imunológicos/farmacologia , Anilidas/farmacologia , Animais , Artralgia/induzido quimicamente , Artralgia/imunologia , Artrite Experimental/induzido quimicamente , Cinamatos/farmacologia , Modelos Animais de Doenças , Feminino , Adjuvante de Freund/farmacologia , Hiperalgesia/induzido quimicamente , Injeções Intra-Articulares , Injeções Espinhais , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Canal de Cátion TRPA1 , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/genética , Canais de Potencial de Receptor Transitório/antagonistas & inibidores , Canais de Potencial de Receptor Transitório/genética , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Adenosine induces airways obstruction in subjects with asthma, but the receptor subtype responsible remains unknown. The objectives of this study were to determine the pharmacological profile of adenosine receptor subtypes mediating contraction and to investigate the mechanism in normal and passively sensitized human airway tissues. Contraction of bronchial rings isolated from resected lung tissue of patients with lung carcinoma was measured in response to nonselective adenosine receptor agonists, 5-AMP and 5'-(N-Ethylcarboxamido)adenosine, and A(1) receptor agonist, N(6)-cyclopentyladenosine, in the absence and presence of selective adenosine receptor antagonists. Pharmacological antagonists, chemical ablation of airway sensory nerves using capsaicin, and passive sensitization of tissue with serum from subjects with atopy and asthma was used to investigate the mechanism of contraction. Human bronchial tissue contracted in a concentration-dependent manner to adenosine agonists that showed a rank order of activity of A(1) > A(2B) >> A2(A) = A3. The maximum contractile response to N(6)-cyclopentyladenosine (231.0 ± 23.8 mg) was significantly reduced in tissues chemically treated with capsaicin to desensitize sensory nerves (desensitized: 101.6 ± 15.2 mg; P < 0.05). Passive sensitization significantly augmented the contraction induced by adenosine A(1) receptor activation (sensitized: 389.7 ± 52.8 mg versus nonsensitized; P < 0.05), which was linked to the release of leukotrienes, and not histamine (MK571: 25.5 ± 1.7 mg; epinastine 260.0 ± 22.2 mg versus control; P < 0.05). This study provides evidence for a role for adenosine A(1) receptors in eliciting human airway smooth muscle constriction, which, in part, is mediated by the action of capsaicin sensitive sensory nerves.
Assuntos
Agonistas do Receptor A1 de Adenosina/farmacologia , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Adenosina/análogos & derivados , Asma/fisiopatologia , Brônquios/fisiopatologia , Broncoconstrição/efeitos dos fármacos , Receptor A1 de Adenosina , Adenosina/farmacologia , Asma/metabolismo , Brônquios/inervação , Brônquios/metabolismo , Capsaicina/farmacologia , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Fármacos do Sistema Sensorial/farmacologia , Vasodilatadores/farmacologiaRESUMO
Roflumilast is a selective once daily, oral phosphodiesterase-4 inhibitor that has recently been registered in all European Union countries as novel targeted therapy for COPD, while FDA approval for the USA market is expected in 2011. In several phase III trials in patients with moderate to (very) severe COPD and in patients with symptoms of chronic bronchitis and recurrent exacerbations, roflumilast showed sustained clinical efficacy by improving lung function and by reducing exacerbation rates. These beneficial effects have also been demonstrated when added to long-acting bronchodilators (both LABA and LAMA), underscoring the anti-inflammatory activity of roflumilast in COPD. Pooled data analysis showed overall mild to moderate, mostly self-limiting adverse events, mainly consisting of nausea, diarrhea and weight loss. In this review we discuss the results of the 4 registration studies showing promising effects of roflumilast in COPD and provide an overview of the topics that still need to be addressed.
Assuntos
Pneumopatias Obstrutivas/tratamento farmacológico , Inibidores da Fosfodiesterase 4/uso terapêutico , Aminopiridinas/farmacocinética , Aminopiridinas/uso terapêutico , Benzamidas/farmacocinética , Benzamidas/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Nucleotídeo Cíclico Fosfodiesterase do Tipo 7/antagonistas & inibidores , Ácidos Cicloexanocarboxílicos/uso terapêutico , Ciclopropanos/farmacocinética , Ciclopropanos/uso terapêutico , Humanos , Nitrilas/uso terapêutico , Inibidores da Fosfodiesterase 4/efeitos adversosRESUMO
The pathophysiological processes underlying respiratory diseases like asthma are complex, resulting in an overwhelming choice of potential targets for the novel treatment of this disease. Despite this complexity, asthmatic subjects are uniquely sensitive to a range of substances like adenosine, thought to act indirectly to evoke changes in respiratory mechanics and in the underlying pathology, and thereby to offer novel insights into the pathophysiology of this disease. Adenosine is of particular interest because this substance is produced endogenously by many cells during hypoxia, stress, allergic stimulation, and exercise. Extracellular adenosine can be measured in significant concentrations within the airways; can be shown to activate adenosine receptor (AR) subtypes on lung resident cells and migrating inflammatory cells, thereby altering their function, and could therefore play a significant role in this disease. Many preclinical in vitro and in vivo studies have documented the roles of the various AR subtypes in regulating cell function and how they might have a beneficial impact in disease models. Agonists and antagonists of some of these receptor subtypes have been developed and have progressed to clinical studies in order to evaluate their potential as novel antiasthma drugs. In this chapter, we will highlight the roles of adenosine and AR subtypes in many of the characteristic features of asthma: airway obstruction, inflammation, bronchial hyperresponsiveness and remodeling. We will also discuss the merit of targeting each receptor subtype in the development of novel antiasthma drugs.
Assuntos
Asma/etiologia , Receptores Purinérgicos P1/fisiologia , Adenosina/metabolismo , Animais , Broncoconstrição/fisiologia , Humanos , Receptor A1 de Adenosina/fisiologia , Receptor A2A de Adenosina/fisiologia , Receptor A2B de Adenosina/fisiologia , Receptor A3 de Adenosina/fisiologiaRESUMO
beta(2)-adrenoceptor agonists are the mainstay for the acute symptomatic treatment of asthma and provide effective bronchoprotection to a wide range of bronchoconstrictor agents. However, over the past 4 decades there has been a continuing debate concerning whether regular chronic treatment with these drugs may be doing more harm than good. The FDA's recent decision to add black box warnings concerning the regular use of salmeterol- and formoterol-containing compounds, as well as their decision not to recommend agents containing long-acting beta(2)-adrenoceptor agonists as first-line therapy, seems to confirm the concerns regarding the regular use of the long-acting beta(2)-adrenoceptor agonists. A similar debate arose in the late 1980s concerning the use of beta-adrenoceptor agonists in the treatment of heart failure. In this disease, short-term use of beta agonists is associated with increased cardiac index and stroke volume, yet their long-term use is associated with increased morbidity and mortality. Moreover, certain beta blockers that are initially detrimental when used short term are now considered beneficial in the treatment of this disease when used chronically. Here, there is a parallel, as beta blockers are contraindicated in patients with asthma but the use of beta blockers chronically has never been evaluated. This begs the question of whether a similar paradigm shift is applicable in the treatment of asthma and whether under certain circumstances the long-term use of certain beta blockers may be useful in the treatment of this disease.
Assuntos
Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Asma/tratamento farmacológico , Agonistas Adrenérgicos beta/efeitos adversos , Agonistas Adrenérgicos beta/uso terapêutico , Antagonistas Adrenérgicos beta/efeitos adversos , Antagonistas Adrenérgicos beta/uso terapêutico , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacologia , Antiasmáticos/uso terapêutico , Asma/fisiopatologia , Agonismo Inverso de Drogas , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , HumanosRESUMO
BACKGROUND: We previously found many transient receptor potential vanilloid receptor subtype 1 (TRPV1) axons in the tracheal smooth muscle and epithelium of the guinea pig airway. One report indicates that the number of TRPV1 axons is significantly increased in patients with cough variant asthma. AIM: To determine whether the distribution of TRPV1 in the airways is altered in guinea pigs with an allergic phenotype. METHODS: Ten guinea pigs were assigned to 2 groups in a double-blind study. Five animals were sensitized with ovalbumin and the other 5 underwent sham sensitization. Cryopreserved sections (30 microm) of tracheal tissues removed from each animal were stained with polyclonal serum rabbit anti-TRPV1 antibody (1:30,000) and examined by confocal microscopy. RESULTS: Axons immunoreactive to TRPV1 localized to fine axons within the epithelium and around areas of smooth muscle, were more densely stained and frequent in the ovalbumin than in the sham group. CONCLUSION: The number of TRPV1-immunoreactive axons in the trachea increases under allergic inflammatory conditions.
Assuntos
Asma/imunologia , Canais de Cátion TRPV/biossíntese , Traqueia/imunologia , Animais , Asma/patologia , Axônios/química , Axônios/imunologia , Modelos Animais de Doenças , Método Duplo-Cego , Cobaias , Imuno-Histoquímica , Masculino , Microscopia Confocal , Ovalbumina/imunologia , Canais de Cátion TRPV/análise , Traqueia/inervação , Traqueia/patologiaRESUMO
Adenosine induces dyspnea, cough, and airways obstruction in asthma, a phenomenon that also occurs in various sensitized animal models in which a neuronal involvement has been implicated. Although adenosine has been suggested to activate cholinergic nerves, the precise mechanism has not been established. In the present study, the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) induced a cholinergic reflex, causing tracheal smooth muscle contraction that was significantly inhibited by the adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 100 microg/kg) (P < 0.05) in anesthetized animals. Furthermore, the adenosine A(2) agonist 2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS-21680) induced a small reflex, whereas the A(3) selective agonist N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyladenosine (IB-MECA) was without effect. The tracheal reflex induced by CPA was also inhibited by recurrent nerve ligation or muscarinic receptor blockade (P < 0.001), indicating that a cholinergic neuronal mechanism of action accounted for this response. The cholinergic reflex in response to aerosolized CPA was significantly greater in passively sensitized compared with naive guinea pigs (P < 0.01). Chronic capsaicin treatment, which inhibited sensory nerve function, failed to inhibit CPA-induced reflex tracheal contractions in passively sensitized guinea pigs, although the local anesthetic lidocaine inhibited CPA-induced tracheal contractions. The effects of CPA on the reflex response was not dependent on the release of histamine from tissue mast cells or endogenous prostaglandins as shown by the lack of effect of the histamine H(1) receptor antagonist pyrilamine (1 mg/kg) or the cyclooxygenase inhibitor meclofenamic acid (3 mg/kg), respectively. In conclusion, activation of pulmonary adenosine A(1) receptors can stimulate cholinergic reflexes, and these reflexes are increased in allergic guinea pigs.
Assuntos
Agonistas do Receptor A1 de Adenosina , Adenosina/farmacologia , Sistema Nervoso Parassimpático/efeitos dos fármacos , Receptor A1 de Adenosina/fisiologia , Traqueia/efeitos dos fármacos , Administração por Inalação , Resistência das Vias Respiratórias/fisiologia , Animais , Células COS , Cálcio/metabolismo , Capsaicina , Chlorocebus aethiops , Tosse/induzido quimicamente , Tosse/fisiopatologia , Relação Dose-Resposta a Droga , Cobaias , Técnicas In Vitro , Injeções Intravenosas , Nervos Laríngeos/fisiologia , Ligadura , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/inervação , Receptor A1 de Adenosina/genética , Reflexo/efeitos dos fármacos , Testes de Função Respiratória , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/fisiologia , TransfecçãoRESUMO
Although in-vitro experiments have suggested that P-glycoprotein (P-gp) may have an important influence on the disposition of inhaled drugs, the effect of P-gp on absorption from the lung in-vivo has not been reported previously. The aim of this study was to compare the pulmonary absorption of digoxin, a well-characterised substrate for P-gp, in mdr1a (-/-) (P-gp-deficient) and mdr1a (+/+) (P-gp-competent) mice. Digoxin was administered by intratracheal instillation over 3-4 s, a method demonstrated to result in dispersion of the dose to all regions of the lung. Drug distribution was determined in the lungs, plasma, brain, heart, liver and kidney of individual mice after 5, 10, 30, 60 and 90 min. Digoxin was cleared rapidly from the lung after intratracheal administration. No differences were observed in the maximum serum concentrations between mdr1a (+/+) and mdr1a (-/-) mice (37.8 +/- 6.9 and 38.8 +/- 15.8 ng mL(-1), respectively). The serum concentration versus time profiles were similar in both strains; the area under the drug serum concentration versus time curve (AUC) was 2010 and 1812 ng mL(-1) min in mdr1a (-/-) and mdr1a (+/+) mice, respectively. For organs harvested at the end of the experiment (90 min), the only significant difference between the strains was the markedly elevated concentration of digoxin in the brains of mdr1a (-/-) mice. In conclusion, digoxin is rapidly absorbed from the mouse lung following tracheal instillation, with no difference in the rate or extent of absorption between mdr1a-deficient and -competent mice. This suggests that, in contrast to the scenario suggested by in-vitro data, P-gp in the respiratory epithelium may have little influence on the disposition of drugs that are well absorbed from the lung.
Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Digoxina/farmacocinética , Pulmão/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/deficiência , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Animais , Área Sob a Curva , Encéfalo/metabolismo , Radioisótopos de Carbono , Cardiotônicos/administração & dosagem , Cardiotônicos/sangue , Cardiotônicos/farmacocinética , Digoxina/administração & dosagem , Digoxina/metabolismo , Feminino , Rim/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Knockout , Miocárdio/metabolismo , Mucosa Respiratória/metabolismo , Fatores de Tempo , TrítioRESUMO
Inhaled adenosine induces airway obstruction in asthmatic but not healthy subjects, a phenomenon that is also observed in various animal species when they are immunised to a relevant antigen, but which does not occur in naïve animals. The purpose of this study was to investigate the mechanisms of airway responsiveness to adenosine receptor agonists in anaesthetised allergic guinea pigs. Inhaled adenosine 5'-monophosphate (AMP), the A1-selective adenosine receptor agonist N6-cyclopentyladenosine (CPA) and ovalbumin all caused airway obstruction in allergic guinea pigs, but not naïve animals, as assessed by changes in total lung resistance. In contrast, the A(2a)-selective (CGS 21680; 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxoamido adenosine) and A3-selective (IB-MECA; 1-deoxy-1-[6-[[3-iodophenyl)-methyl]amino]-9H-purin-9-yl]-N-methyl-beta-D-ribofuranuronamide) adenosine receptor agonists failed to elicit airway obstruction in passively sensitised guinea pigs. Airway obstruction induced by AMP or CPA was not inhibited by the H1 receptor antagonist, mepyramine (1 mg kg(-1)) in passively sensitised guinea-pigs. In contrast, airway obstruction to ovalbumin was significantly inhibited by this antagonist. Airway obstruction induced by AMP and CPA was significantly inhibited in sensitised animals chronically treated with capsaicin. In contrast, airway obstruction to ovalbumin was not inhibited by this treatment. Airway obstruction induced by AMP, CPA and ovalbumin was significantly inhibited following bilateral vagotomy or pharmacological treatment with atropine (2 mg kg(-1)). Airway obstruction to CPA was inhibited by the adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX: 0.1-1 mg kg(-1)). In contrast, airway obstruction to ovalbumin was not inhibited by this treatment. These observations provide evidence indicating that AMP and CPA may induce airway obstruction in sensitised guinea pigs by a mechanism unrelated to histamine release from mast cells, but is mediated via an adenosine A1-receptor-dependent mechanism. The inhibition of AMP- and CPA-induced airway obstruction by atropine, capsaicin and bilateral vagotomy suggests a neuronal-dependent mechanism with the particular involvement of capsaicin-sensitive nerves.