RESUMEN
BACKGROUND: Fibroblast differentiation to a myofibroblast phenotype is a feature of airway remodeling in asthma. Lung fibroblasts express the integrin receptor α4ß7 and fibronectin induces myofibroblast differentiation via this receptor. OBJECTIVES: To investigate the role of the ß7 integrin receptor subunit and α4ß7 integrin complex in airway remodeling and airway hyperresponsiveness (AHR) in a murine model of chronic allergen exposure. METHODS: C57BL/6 wild type (WT) and ß7 integrin null mice (ß7 -/-) were sensitized (days 1,10) and challenged with ovalbumin (OVA) three times a week for one or 4 weeks. Similar experiments were performed with WT mice in the presence or absence of α4ß7 blocking antibodies. Bronchoalveolar (BAL) cell counts, AHR, histological evaluation, soluble collagen content, Transforming growth factor-ß (TGFß) and Interleukin-13 (IL13) were measured. Phenotype of fibroblasts cultured from WT and ß7 -/- saline (SAL) and OVA treated mice was evaluated. RESULTS: Eosinophil numbers were similar in WT vs ß7-/- mice. Prolonged OVA exposure in ß7-/- mice was associated with reduced AHR, lung collagen content, peribronchial smooth muscle, lung tissue TGFß and IL13 expression as compared to WT. Similar findings were observed in WT mice treated with α4ß7 blocking antibodies. Fibroblast migration was enhanced in response to OVA in WT but not ß7 -/- fibroblasts. α-SMA and fibronectin expression were reduced in ß7-/- fibroblasts relative to WT. CONCLUSIONS: The ß7 integrin subunit and the α4ß7 integrin complex modulate AHR and airway remodeling in a murine model of allergen exposure. This effect is, at least in part, explained by inhibition of fibroblast activation and is independent of eosinophilic inflammation.
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Remodelación de las Vías Aéreas (Respiratorias) , Cadenas beta de Integrinas , Ratones Endogámicos C57BL , Ratones Noqueados , Ovalbúmina , Animales , Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Remodelación de las Vías Aéreas (Respiratorias)/inmunología , Ratones , Ovalbúmina/toxicidad , Cadenas beta de Integrinas/metabolismo , Cadenas beta de Integrinas/genética , Alérgenos/inmunología , Alérgenos/toxicidad , Células Cultivadas , Hiperreactividad Bronquial/inmunología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/fisiopatología , Hiperreactividad Bronquial/patología , Pulmón/metabolismo , Pulmón/inmunología , Pulmón/patología , Modelos Animales de Enfermedad , Fibroblastos/metabolismo , Fibroblastos/patología , Fibroblastos/inmunología , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Exposure to particulate matter (PM10) can induce respiratory diseases that are closely related to bronchial hyperresponsiveness. However, the involved mechanism remains to be fully elucidated. This study aimed to demonstrate the effects of PM10 on the acetylcholine muscarinic 3 receptor (CHRM3) expression and the role of the ERK1/2 pathway in rat bronchial smooth muscle. A whole-body PM10 exposure system was used to stimulate bronchial hyperresponsiveness in rats for 2 and 4 months, accompanied by MEK1/2 inhibitor U0126 injection. The whole-body plethysmography system and myography were used to detect the pulmonary and bronchoconstrictor function, respectively. The mRNA and protein levels were determined by Western blotting, qPCR, and immunofluorescence. Enzyme-linked immunosorbent assay was used to detect the inflammatory cytokines. Compared with the filtered air group, 4 months of PM10 exposure significantly increased CHRM3-mediated pulmonary function and bronchial constriction, elevated CHRM3 mRNA and protein expression levels on bronchial smooth muscle, then induced bronchial hyperreactivity. Additionally, 4 months of PM10 exposure caused an increase in ERK1/2 phosphorylation and increased the secretion of inflammatory factors in bronchoalveolar lavage fluid. Treatment with the MEK1/2 inhibitor, U0126 inhibited the PM10 exposure-induced phosphorylation of the ERK1/2 pathway, thereby reducing the PM10 exposure-induced upregulation of CHRM3 in bronchial smooth muscle and CHRM3-mediated bronchoconstriction. U0126 could rescue PM10 exposure-induced pathological changes in the bronchus. In conclusion, PM10 exposure can induce bronchial hyperresponsiveness in rats by upregulating CHRM3, and the ERK1/2 pathway may be involved in this process. These findings could reveal a potential therapeutic target for air pollution induced respiratory diseases.
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Hiperreactividad Bronquial , Material Particulado , Receptor Muscarínico M3 , Animales , Hiperreactividad Bronquial/inducido químicamente , Hiperreactividad Bronquial/fisiopatología , Hiperreactividad Bronquial/metabolismo , Masculino , Material Particulado/toxicidad , Receptor Muscarínico M3/metabolismo , Receptor Muscarínico M3/genética , Ratas , Regulación hacia Arriba/efectos de los fármacos , Bronquios/efectos de los fármacos , Bronquios/metabolismo , Bronquios/patología , Ratas Sprague-Dawley , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Broncoconstricción/efectos de los fármacos , Citocinas/metabolismo , Citocinas/genética , Butadienos , NitrilosAsunto(s)
Asma , Asma/metabolismo , Asma/genética , Humanos , Animales , Hiperreactividad Bronquial/metabolismoRESUMEN
BACKGROUND: Obesity is associated with airway hyperresponsiveness and lung fibrosis, which may reduce the effectiveness of standard asthma treatment in individuals suffering from both conditions. Statins and proprotein convertase subtilisin/kexin-9 inhibitors not only reduce serum cholesterol, free fatty acids but also diminish renin-angiotensin system activity and exhibit anti-inflammatory effects. These mechanisms may play a role in mitigating lung pathologies associated with obesity. METHODS: Male C57BL/6 mice were induced to develop obesity through high-fat diet for 16 weeks. Conditional TGF-ß1 transgenic mice were fed a normal diet. These mice were given either atorvastatin or proprotein convertase subtilisin/kexin-9 inhibitor (alirocumab), and the impact on airway hyperresponsiveness and lung pathologies was assessed. RESULTS: High-fat diet-induced obesity enhanced airway hyperresponsiveness, lung fibrosis, macrophages in bronchoalveolar lavage fluid, and pro-inflammatory mediators in the lung. These lipid-lowering agents attenuated airway hyperresponsiveness, macrophages in BALF, lung fibrosis, serum leptin, free fatty acids, TGF-ß1, IL-1ß, IL-6, and IL-17a in the lung. Furthermore, the increased RAS, NLRP3 inflammasome, and cholecystokinin in lung tissue of obese mice were reduced with statin or alirocumab. These agents also suppressed the pro-inflammatory immune responses and lung fibrosis in TGF-ß1 over-expressed transgenic mice with normal diet. CONCLUSIONS: Lipid-lowering treatment has the potential to alleviate obesity-induced airway hyperresponsiveness and lung fibrosis by inhibiting the NLRP3 inflammasome, RAS and cholecystokinin activity.
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Dieta Alta en Grasa , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Ratones Endogámicos C57BL , Ratones Transgénicos , Obesidad , Fibrosis Pulmonar , Animales , Masculino , Dieta Alta en Grasa/efectos adversos , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Ratones , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Fibrosis Pulmonar/prevención & control , Fibrosis Pulmonar/patología , Fibrosis Pulmonar/metabolismo , Fibrosis Pulmonar/tratamiento farmacológico , Inhibidores de PCSK9 , Atorvastatina/farmacología , Atorvastatina/uso terapéutico , Ratones Obesos , Proproteína Convertasa 9/metabolismo , Proproteína Convertasa 9/genética , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Hiperreactividad Bronquial/prevención & control , Hiperreactividad Bronquial/tratamiento farmacológico , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/fisiopatología , Anticuerpos Monoclonales HumanizadosRESUMEN
Oxygen therapy provides an important treatment for preterm and low-birth-weight neonates, however, it has been shown that prolonged exposure to high levels of oxygen (hyperoxia) is one of the factors contributing to the development of bronchopulmonary dysplasia (BPD) by inducing lung injury and airway hyperreactivity. There is no effective therapy against the adverse effects of hyperoxia. Therefore, this study was undertaken to test the hypothesis that natural phytoalexin resveratrol will overcome hyperoxia-induced airway hyperreactivity, oxidative stress, and lung inflammation. Newborn rats were exposed to hyperoxia (fraction of inspired oxygen - FiO2>95 % O2) or ambient air (AA) for seven days. Resveratrol was supplemented either in vivo (30 mg·kg-1·day-1) by intraperitoneal administration or in vitro to the tracheal preparations in an organ bath (100 mikroM). Contractile and relaxant responses were studied in tracheal smooth muscle (TSM) using the in vitro organ bath system. To explain the involvement of nitric oxide in the mechanisms of the protective effect of resveratrol against hyperoxia, a nitric oxide synthase inhibitor - Nomega-nitro-L-arginine methyl ester (L-NAME), was administered in some sets of experiments. The superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and the tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in the lungs were determined. Resveratrol significantly reduced contraction and restored the impaired relaxation of hyperoxia-exposed TSM (p<0.001). L-NAME reduced the inhibitory effect of resveratrol on TSM contractility, as well as its promotion relaxant effect (p<0.01). Resveratrol preserved the SOD and GPx activities and decreased the expression of TNF-alpha and IL-1beta in hyperoxic animals. The findings of this study demonstrate the protective effect of resveratrol against hyperoxia-induced airway hyperreactivity and lung damage and suggest that resveratrol might serve as a therapy to prevent the adverse effects of neonatal hyperoxia. Keywords: Bronchopulmonary dysplasia, Hyperoxia, Airway hyperreactivity, Resveratrol, Pro-inflammatory cytokines.
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Animales Recién Nacidos , Displasia Broncopulmonar , Modelos Animales de Enfermedad , Estrés Oxidativo , Neumonía , Resveratrol , Animales , Resveratrol/farmacología , Estrés Oxidativo/efectos de los fármacos , Displasia Broncopulmonar/prevención & control , Displasia Broncopulmonar/metabolismo , Neumonía/prevención & control , Neumonía/metabolismo , Neumonía/inducido químicamente , Ratas , Hiperoxia/complicaciones , Hiperoxia/metabolismo , Estilbenos/farmacología , Estilbenos/uso terapéutico , Antioxidantes/farmacología , Hiperreactividad Bronquial/prevención & control , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/fisiopatología , Hiperreactividad Bronquial/inducido químicamente , Ratas Sprague-Dawley , MasculinoRESUMEN
AIMS: Augmented smooth muscle contractility of the airways associated with an increased expression of RhoA, a monomeric GTPase responsible for Ca2+ sensitization of contraction, is one of the causes of airway hyperresponsiveness. However, the mechanism of the altered properties of airway smooth muscle cells, including the RhoA upregulation, is not fully understood. This study aims to define functional role of a long non-coding RNA MALAT1 in the RhoA expression and development of bronchial smooth muscle (BSM) hyper-contractility. MAIN METHODS: Cultured human BSM cells were transfected with MALAT1 antisense oligonucleotide (AS), miR-133a-3p mimic, and/or inhibitor, and then stimulated with interleukin-13 (IL-13). In animal experiments, the ovalbumin (OA)-sensitized mice were repeatedly challenged with aerosolized OA to induce asthmatic reaction. KEY FINDINGS: Treatment of the cells with IL-13 induced an increase in RhoA protein. Either MALAT1 AS or miR-133a-3p mimic transfection inhibited the IL-13-induced upregulation of RhoA. The inhibitory effect of MALAT1 AS was abolished by co-transfection with miR-133a-3p inhibitor. In BSMs of the murine asthma model, upregulations of Malat1 and RhoA protein were observed concomitantly with downregulation of miR-133a-3p. SIGNIFICANCE: These findings suggest that MALAT1 positively regulates RhoA protein expression by inhibiting miR-133a-3p in BSM cells, and that its upregulation causes the RhoA upregulation, resulting in an augmented BSM contractility.
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Asma , ARN Largo no Codificante , Proteína de Unión al GTP rhoA , Animales , Humanos , Ratones , Asma/metabolismo , Bronquios/metabolismo , Bronquios/patología , Hiperreactividad Bronquial/metabolismo , Interleucina-13/metabolismo , MicroARNs/metabolismo , Miocitos del Músculo Liso/metabolismo , Proteína de Unión al GTP rhoA/genética , Proteína de Unión al GTP rhoA/metabolismo , ARN Largo no Codificante/metabolismoRESUMEN
PURPOSE: Extracellular acidification is a major component of tissue inflammation, including airway inflammation. The extracellular proton-sensing mechanisms are inherent in various cells including airway structural cells, although their physiological and pathophysiological roles in bronchial smooth muscles (BSMs) are not fully understood. In the present study, to explore the functional role of extracellular acidification on the BSM contraction, the isolated mouse BSMs were exposed to acidic pH under contractile stimulation. METHODS AND RESULTS: The RT-PCR analyses revealed that the proton-sensing G protein-coupled receptors were expressed both in mouse BSMs and cultured human BSM cells. In the mouse BSMs, change in the extracellular pH from 8.0 to 6.8 caused an augmentation of contraction induced by acetylcholine. Interestingly, the acidic pH-induced BSM hyper-contraction was further augmented in the mice that were sensitized and repeatedly challenged with ovalbumin antigen. In this animal model of asthma, upregulations of G protein-coupled receptor 68 (GPR68) and GPR65, that were believed to be coupled with Gq and Gs proteins respectively, were observed, indicating that the acidic pH could cause hyper-contraction probably via an activation of GPR68. However, psychosine, a putative antagonist for GPR68, failed to block the acidic pH-induced responses. CONCLUSION: These findings suggest that extracellular acidification contributes to the airway hyperresponsiveness, a characteristic feature of bronchial asthma. Further studies are required to identify the receptor(s) responsible for sensing extracellular protons in BSM cells.
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Asma , Hiperreactividad Bronquial , Acetilcolina/efectos adversos , Acetilcolina/metabolismo , Animales , Bronquios , Hiperreactividad Bronquial/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Inflamación/metabolismo , Ratones , Ratones Endogámicos BALB C , Músculo Liso/metabolismo , Ovalbúmina , Protones , Psicosina/efectos adversos , Psicosina/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
Group 2 innate lymphoid cells (ILC2s) have emerged as critical mediators in driving allergic airway inflammation. Here, we identified angiotensin (Ang) II as a positive regulator of ILC2s. ILC2s expressed higher levels of the Ang II receptor AT1a, and colocalized with lung epithelial cells expressing angiotensinogen. Administration of Ang II significantly enhanced ILC2 responses both in vivo and in vitro, which were almost completely abrogated in AT1a-deficient mice. Deletion of AT1a or pharmacological inhibition of the Ang II-AT1 axis resulted in a remarkable remission of airway inflammation. The regulation of ILC2s by Ang II was cell intrinsic and dependent on interleukin (IL)-33, and was associated with marked changes in transcriptional profiling and up-regulation of ERK1/2 phosphorylation. Furthermore, higher levels of plasma Ang II correlated positively with the abundance of circulating ILC2s as well as disease severity in asthmatic patients. These observations reveal a critical role for Ang II in regulating ILC2 responses and airway inflammation.
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Angiotensina II/metabolismo , Inmunidad Innata , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/metabolismo , Receptor de Angiotensina Tipo 1/metabolismo , Enfermedades Respiratorias/etiología , Enfermedades Respiratorias/metabolismo , Animales , Biomarcadores , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/patología , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Inflamación , Interleucina-33/metabolismo , Ratones , Ratones Noqueados , Receptor de Angiotensina Tipo 1/genética , Enfermedades Respiratorias/patologíaRESUMEN
Asthma, characterized by airway hyperresponsiveness, inflammation and remodeling, is a chronic airway disease with complex etiology. Severe asthma is characterized by frequent exacerbations and poor therapeutic response to conventional asthma therapy. A clear understanding of cellular and molecular mechanisms of asthma is critical for the discovery of novel targets for optimal therapeutic control of asthma. Metabolomics is emerging as a powerful tool to elucidate novel disease mechanisms in a variety of diseases. In this review, we summarize the current status of knowledge in asthma metabolomics at systemic and cellular levels. The findings demonstrate that various metabolic pathways, related to energy metabolism, macromolecular biosynthesis and redox signaling, are differentially modulated in asthma. Airway smooth muscle cell plays pivotal roles in asthma by contributing to airway hyperreactivity, inflammatory mediator release and remodeling. We posit that metabolomic profiling of airway structural cells, including airway smooth muscle cells, will shed light on molecular mechanisms of asthma and airway hyperresponsiveness and help identify novel therapeutic targets.
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Asma , Hiperreactividad Bronquial , Asma/metabolismo , Hiperreactividad Bronquial/metabolismo , Humanos , Inflamación , Metabolómica , Miocitos del Músculo Liso/metabolismoRESUMEN
The proton-sensing receptor, ovarian cancer G protein-coupled receptor (OGR1), has been shown to be expressed in airway smooth muscle (ASM) cells and is capable of promoting ASM contraction in response to decreased extracellular pH. OGR1 knockout (OGR1KO) mice are reported to be resistant to the asthma features induced by inhaled allergen. We recently described certain benzodiazepines as OGR1 activators capable of mediating both procontractile and prorelaxant signaling in ASM cells. Here we assess the effect of treatment with the benzodiazepines lorazepam or sulazepam on the asthma phenotype in wild-type (WT) and OGR1KO mice subjected to inhaled house dust mite (HDM; Dermatophagoides pteronyssius) challenge for 3 wk. In contrast to previously published reports, both WT and OGR1KO mice developed significant allergen-induced lung inflammation and airway hyperresponsiveness (AHR). In WT mice, treatment with sulazepam (a Gs-biased OGR1 agonist), but not lorazepam (a balanced OGR1 agonist), prevented allergen-induced AHR, although neither drug inhibited lung inflammation. The protection from development of AHR conferred by sulazepam was absent in OGR1KO mice. Treatment of WT mice with sulazepam also resulted in significant inhibition of HDM-induced collagen accumulation in the lung tissue. These findings suggest that OGR1 expression is not a requirement for development of the allergen-induced asthma phenotype, but OGR1 can be targeted by the Gs-biased OGR1 agonist sulazepam (but not the balanced agonist lorazepam) to protect from allergen-induced AHR, possibly mediated via suppression of chronic bronchoconstriction and airway remodeling in the absence of effects on airway inflammation.
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Alérgenos/toxicidad , Asma/patología , Hiperreactividad Bronquial/patología , Broncoconstricción , Citocinas/metabolismo , Neumonía/patología , Receptores Acoplados a Proteínas G/fisiología , Animales , Ansiolíticos/farmacología , Asma/etiología , Asma/metabolismo , Benzodiazepinas/farmacología , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Femenino , Lorazepam/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Neumonía/etiología , Neumonía/metabolismo , PyroglyphidaeRESUMEN
Increased insulin is associated with obesity-related airway hyperreactivity and asthma. We tested whether the use of metformin, an antidiabetic drug used to reduce insulin resistance, can reduce circulating insulin, thereby preventing airway hyperreactivity in rats with dietary obesity. Male and female rats were fed a high- or low-fat diet for 5 wk. Some male rats were simultaneously treated with metformin (100 mg/kg orally). In separate experiments, after 5 wk of a high-fat diet, some rats were switched to a low-fat diet, whereas others continued a high-fat diet for an additional 5 wk. Bronchoconstriction and bradycardia in response to bilateral electrical vagus nerve stimulation or to inhaled methacholine were measured in anesthetized and vagotomized rats. Body weight, body fat, caloric intake, fasting glucose, and insulin were measured. Vagally induced bronchoconstriction was potentiated only in male rats on a high-fat diet. Males gained more body weight, body fat, and had increased levels of fasting insulin compared with females. Metformin prevented development of vagally induced airway hyperreactivity in male rats on high-fat diet, in addition to inhibiting weight gain, fat gain, and increased insulin. In contrast, switching rats to a low-fat diet for 5 wk reduced body weight and body fat, but it did not reverse fasting glucose, fasting insulin, or potentiation of vagally induced airway hyperreactivity. These data suggest that medications that target insulin may be effective treatment for obesity-related asthma.
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Asma/tratamiento farmacológico , Hiperreactividad Bronquial/tratamiento farmacológico , Broncoconstricción , Dieta Alta en Grasa/efectos adversos , Hiperinsulinismo/prevención & control , Metformina/farmacología , Obesidad/complicaciones , Animales , Asma/inducido químicamente , Asma/metabolismo , Asma/patología , Hiperreactividad Bronquial/inducido químicamente , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/patología , Broncoconstrictores/toxicidad , Femenino , Glucosa/metabolismo , Hiperinsulinismo/etiología , Hiperinsulinismo/metabolismo , Hiperinsulinismo/patología , Hipoglucemiantes/farmacología , Masculino , Cloruro de Metacolina/toxicidad , Ratas , Ratas Sprague-Dawley , Nervio Vago/efectos de los fármacos , Aumento de PesoRESUMEN
Cycloastragenol (CAG), a secondary metabolite from the roots of Astragalus zahlbruckneri, has been reported to exert antiinflammatory effects in heart, skin and liver diseases. However, its role in asthma remains unclear. The present study aimed to investigate the effect of CAG on airway inflammation in an ovalbumin (OVA)induced mouse asthma model. The current study evaluated the lung function and levels of inflammation and autophagy via measurement of airway hyperresponsiveness (AHR), lung histology examination, inflammatory cytokine measurement and western blotting, amongst other techniques. The results demonstrated that CAG attenuated OVAinduced AHR in vivo. In addition, the total number of leukocytes and eosinophils, as well as the secretion of inflammatory cytokines, including interleukin (IL)5, IL13 and immunoglobulin E were diminished in bronchoalveolar lavage fluid of the OVAinduced murine asthma model. Histological analysis revealed that CAG suppressed inflammatory cell infiltration and goblet cell secretion. Notably, based on molecular docking simulation, CAG was demonstrated to bind to the active site of autophagyrelated gene 4microtubuleassociated proteins light chain 3 complex, which explains the reduced autophagic flux in asthma caused by CAG. The expression levels of proteins associated with autophagy pathways were inhibited following treatment with CAG. Taken together, the results of the present study suggest that CAG exerts an antiinflammatory effect in asthma, and its role may be associated with the inhibition of autophagy in lung cells.
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Antiasmáticos/farmacología , Asma/etiología , Autofagia/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Sapogeninas/farmacología , Animales , Asma/tratamiento farmacológico , Asma/metabolismo , Proteínas Relacionadas con la Autofagia/antagonistas & inhibidores , Proteínas Relacionadas con la Autofagia/química , Proteínas Relacionadas con la Autofagia/metabolismo , Biomarcadores , Biopsia , Hiperreactividad Bronquial/tratamiento farmacológico , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Líquido del Lavado Bronquioalveolar , Citocinas/metabolismo , Manejo de la Enfermedad , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Femenino , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunohistoquímica , Mediadores de Inflamación/metabolismo , Ratones , Proteínas Asociadas a Microtúbulos/antagonistas & inhibidores , Proteínas Asociadas a Microtúbulos/química , Proteínas Asociadas a Microtúbulos/metabolismo , Sapogeninas/química , Relación Estructura-ActividadRESUMEN
Ozone is a highly reactive environmental pollutant with well-recognized adverse effects on lung health. Bronchial hyperresponsiveness (BHR) is one consequence of ozone exposure, particularly for individuals with underlying lung disease. Our data demonstrated that ozone induced substantial ATP release from human airway epithelia in vitro and into the airways of mice in vivo and that ATP served as a potent inducer of mast cell degranulation and BHR, acting through P2X7 receptors on mast cells. Both mast cell-deficient and P2X7 receptor-deficient (P2X7-/-) mice demonstrated markedly attenuated BHR to ozone. Reconstitution of mast cell-deficient mice with WT mast cells and P2X7-/- mast cells restored ozone-induced BHR. Despite equal numbers of mast cells in reconstituted mouse lungs, mice reconstituted with P2X7-/- mast cells demonstrated significantly less robust BHR than mice reconstituted with WT mast cells. These results support a model where P2X7 on mast cells and other cell types contribute to ozone-induced BHR.
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Adenosina Trifosfato/metabolismo , Hiperreactividad Bronquial/metabolismo , Mastocitos/metabolismo , Ozono/efectos adversos , Animales , Femenino , Humanos , RatonesRESUMEN
Obesity-related asthma often presents with more severe symptoms than non-obesity-related asthma and responds poorly to current treatments. Both insulin resistance and hyperinsulinemia are common in obesity. We have shown that increased insulin mediates airway hyperreactivity in diet-induced obese rats by causing neuronal M2 muscarinic receptor dysfunction, which normally inhibits acetylcholine release from parasympathetic nerves. Decreasing insulin with streptozotocin prevented airway hyperreactivity and M2 receptor dysfunction. The objective of the present study was to investigate whether pioglitazone, a hypoglycemic drug, prevents airway hyperreactivity and M2 receptor dysfunction in obese rats. Male rats fed a low- or high-fat diet were treated with pioglitazone or PBS by daily gavage. Body weight, body fat, fasting insulin, and bronchoconstriction and bradycardia in response to electrical stimulation of vagus nerves and to aerosolized methacholine were recorded. Pilocarpine, a muscarinic receptor agonist, was used to measure M2 receptor function. Rats on a high-fat diet had potentiated airway responsiveness to vagal stimulation and dysfunctional neuronal M2 receptors, whereas airway responsiveness to methacholine was unaffected. Pioglitazone reduced fasting insulin and prevented airway hyperresponsiveness and M2 receptor dysfunction but did not change inflammatory cytokine mRNA expression in alveolar macrophages. High-fat diet, with and without pioglitazone, had tissue-specific effects on insulin receptor mRNA expression. In conclusion, pioglitazone prevents vagally mediated airway hyperreactivity and protects neuronal M2 muscarinic receptor function in obese rats.
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Hiperreactividad Bronquial/tratamiento farmacológico , Hiperinsulinismo/tratamiento farmacológico , Insulina/metabolismo , Neuronas/efectos de los fármacos , Obesidad/complicaciones , Pioglitazona/farmacología , Receptor Muscarínico M2/metabolismo , Animales , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/patología , Dieta Alta en Grasa/efectos adversos , Hiperinsulinismo/etiología , Hiperinsulinismo/metabolismo , Hiperinsulinismo/patología , Hipoglucemiantes/farmacología , Masculino , Neuronas/metabolismo , Neuronas/patología , Ratas , Ratas Sprague-Dawley , Receptor Muscarínico M2/genéticaRESUMEN
PURPOSE: Augmented bronchial smooth muscle (BSM) contraction is a cause of airway hyperresponsiveness (AHR) in asthma. Increasing evidence suggest that C-C motif chemokine 2 (CCL2) modulates smooth muscle contractility by activating its binding partner C-C chemokine receptor type 2 (CCR2). In the present study, changes in the gene expression of CCL2/CCR2 axis were determined in the BSMs of a murine model of allergic asthma. MATERIALS AND METHODS: The ovalbumin (OA)-sensitized mice were repeatedly challenged with aerosolized OA to induce asthmatic reaction. Twenty-four hours after the last antigen challenge, total RNAs of the main BSM tissues and bronchoalveolar lavage fluids (BALFs) were obtained. RESULTS: Our published microarray data (GEO accession No. GSE116504) detected changes in gene expression associated with the chemokine signaling pathway (KEGG Map ID: 04062) in BSMs of mice with AHR induced by antigen exposure. Among them, quantitative RT-PCR analyses showed significant increase in mRNA expression of Ccl2 and Ccr2. Analysis of BALFs also revealed a significant increase in Ccl2 protein in the airways of the diseased animals. CONCLUSION: It is thus possible that, in association with the AHR, the CCL2/CCR2 axis is enhanced in the airways of allergic bronchial asthma.
Asunto(s)
Alérgenos/farmacología , Asma/metabolismo , Bronquios/metabolismo , Hiperreactividad Bronquial/metabolismo , Proteínas de Unión al ADN/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Expresión Génica , Músculo Liso/metabolismo , Receptores CCR2/metabolismo , Factores de Transcripción/metabolismo , Animales , Asma/etiología , Asma/fisiopatología , Hiperreactividad Bronquial/fisiopatología , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos BALB CRESUMEN
Obesity increases incidence and severity of asthma but the molecular mechanisms are not completely understood. Hyperinsulinemia potentiates vagally induced bronchoconstriction in obese rats. Since bronchoconstriction results from airway smooth muscle contraction, we tested whether insulin changed agonist-induced airway smooth muscle contraction. Obesity-prone and resistant rats were fed a low-fat diet for 5 wk and treated with insulin (Lantus, 3 units/rat sc) 16 h before vagally induced bronchoconstriction was measured. Ex vivo, contractile responses to methacholine were measured in isolated rat tracheal rings and human airway smooth muscle strips before and after incubation (0.5-2 h) with 100 nM insulin or 13.1 nM insulin like growth factor-1 (IGF-1). M2 and M3 muscarinic receptor mRNA expression was quantified by qRT-PCR and changes in intracellular calcium were measured in response to methacholine or serotonin in isolated rat tracheal smooth muscle cells treated with 1 µM insulin. Insulin, administered to animals 16 h prior, potentiated vagally induced bronchoconstriction in both obese-prone and resistant rats. Insulin, not IGF-1, significantly increased methacholine-induced contraction of rat and human isolated airway smooth muscle. In cultured rat tracheal smooth muscle cells, insulin significantly increased M2, not M3, mRNA expression and enhanced methacholine- and serotonin-induced increase in intracellular calcium. Insulin alone did not cause an immediate increase in intracellular calcium. Thus, insulin acutely potentiated agonist-induced increase in intracellular calcium and airway smooth muscle contraction. These findings may explain why obese individuals with hyperinsulinemia are prone to airway hyperreactivity and give insights into future targets for asthma treatment.
Asunto(s)
Hiperreactividad Bronquial/patología , Broncoconstricción , Hiperinsulinismo/complicaciones , Insulina/efectos adversos , Cloruro de Metacolina/farmacología , Contracción Muscular , Músculo Liso/patología , Animales , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Calcio/metabolismo , Humanos , Hipoglucemiantes/efectos adversos , Masculino , Agonistas Muscarínicos/farmacología , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Obesidad/complicaciones , Ratas , Ratas Sprague-Dawley , Receptores Muscarínicos/metabolismo , Tráquea/efectos de los fármacos , Tráquea/patología , Nervio Vago/fisiopatologíaRESUMEN
Supplemental O2 (hyperoxia) is necessary for preterm infant survival but is associated with development of bronchial airway hyperreactivity and childhood asthma. Understanding early mechanisms that link hyperoxia to altered airway structure and function are key to developing advanced therapies. We previously showed that even moderate hyperoxia (50% O2) enhances intracellular calcium ([Ca2+]i) and proliferation of human fetal airway smooth muscle (fASM), thereby facilitating bronchoconstriction and remodeling. Here, we introduce cellular clock biology as a novel mechanism linking early oxygen exposure to airway biology. Peripheral, intracellular clocks are a network of transcription-translation feedback loops that produce circadian oscillations with downstream targets highly relevant to airway function and asthma. Premature infants suffer circadian disruption whereas entrainment strategies improve outcomes, highlighting the need to understand relationships between clocks and developing airways. We hypothesized that hyperoxia impacts clock function in fASM and that the clock can be leveraged to attenuate deleterious effects of O2 on the developing airway. We report that human fASM express core clock machinery (PER1, PER2, CRY1, ARNTL/BMAL1, CLOCK) that is responsive to dexamethasone (Dex) and altered by O2. Disruption of the clock via siRNA-mediated PER1 or ARNTL knockdown alters store-operated calcium entry (SOCE) and [Ca2+]i response to histamine in hyperoxia. Effects of O2 on [Ca2+]i are rescued by driving expression of clock proteins, via effects on the Ca2+ channels IP3R and Orai1. These data reveal a functional fASM clock that modulates [Ca2+]i regulation, particularly in hyperoxia. Harnessing clock biology may be a novel therapeutic consideration for neonatal airway diseases following prematurity.
Asunto(s)
Bronquios/metabolismo , Hiperreactividad Bronquial/metabolismo , Calcio/metabolismo , Relojes Circadianos , Hiperoxia/fisiopatología , Músculo Liso/metabolismo , Oxígeno/metabolismo , Animales , Bronquios/patología , Hiperreactividad Bronquial/patología , Proliferación Celular , Células Cultivadas , Femenino , Feto/metabolismo , Feto/patología , Humanos , Recién Nacido , Masculino , Ratones Endogámicos C57BL , Músculo Liso/patologíaRESUMEN
Asthma is a disease that consists of three main components: airway inflammation, airway hyperresponsiveness, and airway remodeling. Persistent airway inflammation leads to the destruction and degeneration of normal airway tissues, resulting in thickening of the airway wall, decreased reversibility, and increased airway hyperresponsiveness. The progression of irreversible airway narrowing and the associated increase in airway hyperresponsiveness are major factors in severe asthma. This has led to the identification of effective pharmacological targets and the recognition of several biomarkers that enable a more personalized approach to asthma. However, the efficacies of current antibody therapeutics and biomarkers are still unsatisfactory in clinical practice. The establishment of an ideal phenotype classification that will predict the response of antibody treatment is urgently needed. Here, we review recent advancements in antibody therapeutics and novel findings related to the disease process for severe asthma.
Asunto(s)
Anticuerpos/inmunología , Asma/inmunología , Asma/terapia , Bronquios/inmunología , Inflamación/inmunología , Animales , Asma/metabolismo , Biomarcadores/metabolismo , Bronquios/metabolismo , Hiperreactividad Bronquial/inmunología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/terapia , Humanos , Inflamación/metabolismoRESUMEN
Allergic asthma remains an important worldwide health issue. Animal models are valuable for understanding the pathophysiological mechanisms of asthma and the development of effective therapeutics. This study aims to develop an alternative murine model induced by shrimp tropomyosin (ST) instead of ovalbumin (OVA). To investigate responses to short-term exposure to antigens, mice were sensitized with intraperitoneal injections of ST or ST plus aluminum adjuvant on days 0, 7, 14 followed by an intranasal challenge with ST for seven consecutive days. We reveal that sensitization with ST alone or ST plus aluminum induces significant levels of serum total IgE and ST-specific IgE in mice. Challenge results show that ST causes severe eosinophilic airway inflammation. Histology analysis of the lung tissues demonstrates airway inflammation and mucus hypersecretion within the bronchi in mice exposed to ST. Analysis of the cell composition in bronchoalveolar lavage fluid (BALF) shows a significant increase in eosinophil count in ST alone and ST plus aluminum groups. We also detect increased CD4+ T lymphocytes in lung tissues and production of helper T cell type 2-associated cytokines (IL-4 and IL-5) in BALF. In addition, airway hyperresponsiveness to methacholine in ST alone and ST plus aluminum groups is much higher than that in control groups. For the chronic model, mice were sensitized by ST or ST plus aluminum adjuvant for 3weeks and challenged with ST for 6weeks. We find severe structural changes in animals upon prolonged exposure to ST, including goblet cell hyperplasia, collagen deposition, and smooth muscle thickening. In conclusion, ST-induced asthma is a simple murine model for studying pathogenesis of asthma and evaluating new therapeutic drugs.
Asunto(s)
Alérgenos , Asma/inducido químicamente , Hiperreactividad Bronquial/inducido químicamente , Pulmón/inmunología , Penaeidae/inmunología , Tropomiosina , Adyuvantes Inmunológicos , Animales , Asma/inmunología , Asma/metabolismo , Asma/patología , Hiperreactividad Bronquial/inmunología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/fisiopatología , Broncoconstricción , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Inmunoglobulina E/sangre , Interleucina-4/metabolismo , Interleucina-5/metabolismo , Pulmón/metabolismo , Pulmón/patología , Pulmón/fisiopatología , Ratones Endogámicos C57BL , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Factores de TiempoRESUMEN
BACKGROUND: Asthma is a widespread, multifactorial chronic airway disease. The influence of regulatory B cells on airway hyperreactivity (AHR) and remodeling in asthma is poorly understood. OBJECTIVE: Our aim was to analyze the role of B cells in a house dust mite (HDM)-based murine asthma model. METHODS: The influence of B cells on lung function, tissue remodeling, and the immune response were analyzed by using wild-type and B-cell-deficient (µMT) mice and transfer of IL-10-proficient and IL-10-deficient B cells to µMT mice. RESULTS: After HDM-sensitization, both wild-type and µMT mice developed AHR, but the AHR was significantly stronger in µMT mice, as confirmed by 2 independent techniques: invasive lung function measurement in vivo and examination of precision-cut lung slices ex vivo. Moreover, airway remodeling was significantly increased in allergic µMT mice, as shown by enhanced collagen deposition in the airways, whereas the numbers of FoxP3+ and FoxP3- IL-10-secreting regulatory T cells were reduced. Adoptive transfer of IL-10-proficient but not IL-10-deficient B cells into µMT mice before HDM-sensitization attenuated AHR and lung remodeling. In contrast, FoxP3+ regulatory T cells were equally upregulated by transfer of IL-10-proficient and IL-10-deficient B cells. CONCLUSION: Our data in a murine asthma model illustrate a central role of regulatory B cells in the control of lung function and airway remodeling and may support future concepts for B-cell-targeted prevention and treatment strategies for allergic asthma.