RESUMO
BACKGROUND: Prophylactic administration of mesenchymal stromal cells (MSCs) derived from adipose (AD-MSC) and bone marrow tissue (BM-MSC) in ovalbumin-induced asthma hinders inflammation in a Treg-dependent manner. It is uncertain whether MSCs act through Tregs when inflammation is already established in asthma induced by a clinically relevant allergen. OBJECTIVE: Evaluate the effect of therapeutic administration of MSCs on inflammation and Treg cells in house dust mite (HDM)-induced asthma. METHODS: BM-MSCs and AD-MSCs were administered intratracheally to C57BL/6 mice 1 day after the last HDM challenge. Lung function, remodelling and parenchymal inflammation were assayed 3 or 7 days after MSCs treatment, through invasive plethysmography and histology, respectively. Bronchoalveolar lavage fluid (BALF) and mediastinal lymph nodes (mLNs) were assessed regarding the inflammatory profile by flow cytometry, ELISA and qRT-PCR. MSCs were studied regarding their potential to induce Treg cells from primed and unprimed lymphocytes in vitro. RESULTS: BM-MSCs, but not AD-MSCs, reduced lung influx of eosinophils and B cells and increased IL-10 levels in HDM-challenged mice. Neither BM-MSCs nor AD-MSCs reduced lung parenchymal inflammation, airway hyperresponsiveness or mucus hypersecretion. BM-MSCs and AD-MSCs did not up-regulate Treg cell counts within the airways and mLNs, but BM-MSCs decreased the pro-inflammatory profile of alveolar macrophages. Co-culture of BM-MSCs and AD-MSCs with allergen-stimulated lymphocytes reduced Treg cell counts in a cell-to-cell contact-independent manner, although co-culture of both MSCs with unprimed lymphocytes up-regulated Treg cell counts. CONCLUSIONS: MSCs therapeutically administered exert anti-inflammatory effects in the airway of HDM-challenged mice, but do not ameliorate lung function or remodelling. Although MSC pre-treatment can increase Treg cell numbers, it is highly unlikely that the MSCs will induce Treg cell expansion when lymphocytes are allergenically primed in an established lung inflammation.
Assuntos
Asma/imunologia , Asma/terapia , Imunomodulação , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Linfócitos T Reguladores/imunologia , Alérgenos/imunologia , Animais , Asma/diagnóstico , Asma/metabolismo , Biópsia , Comunicação Celular , Técnicas de Cocultura , Modelos Animais de Doenças , Ativação Linfocitária/imunologia , Camundongos , Camundongos Transgênicos , Pyroglyphidae/imunologia , Testes de Função Respiratória , Linfócitos T Reguladores/metabolismoRESUMO
The extracellular matrix represents the three-dimensional scaffold of the alveolar wall, which is composed of a layer of epithelial and endothelial cells, their basal membrane, and a thin interstitial layer containing fibrous proteins, glycoproteins, glycosaminoglycans, and proteoglycans. Mechanical ventilation with low and high tidal volumes can induce proteoglycan fragmentation, which may cause activation of the inflammatory cascade, leading to the main features of ventilator-induced lung injury (VILI): alveolar edema and collagen deposition. The purpose of this article is to describe VILI pathophysiology with a special focus on the effects of mechanical ventilation on the extracellular matrix. A more complete understanding of the molecular effects induced by physical forces is required to better assess the impact of existing mechanical ventilation strategies, as well as to develop new therapeutic strategies to reduce lung damage.
Assuntos
Matriz Extracelular , Lesão Pulmonar , Respiração Artificial , Lesão Pulmonar Induzida por Ventilação Mecânica , Matriz Extracelular/fisiologia , Humanos , Pulmão , Lesão Pulmonar/terapia , Volume de Ventilação PulmonarRESUMO
We determined the accuracy of distensibility index of inferior vena cava (dIVC) for evaluation of fluid responsiveness in rats with acute respiratory distress syndrome (ARDS) and validated this index for use in rat models. In protocol 1, E. coli lipopolysaccharide was administered in Wistar rats (n=7). After 24h, animals were mechanically ventilated, and stroke volume (SV) and dIVC quantified after blood drainage and subsequent volume expansion (albumin 20%). A receiver operating characteristic (ROC) curve was plotted to determine the optimal dIVC cutoff. In protocol 2, rats (n=10) were divided into fluid-responders (SV increase >5%) and nonresponders (SV increase <5%). The dIVC cutoff obtained from protocol 1 was 25%. Fluid responders had a 2.5 relative risk of low dIVC (<25%). The sensitivity, specificity, positive predictive, and negative predictive values for dIVC were 74%, 62%, 59%, and 76%, respectively. In conclusion, a dIVC threshold <25% was associated with positive response after volume expansion and could be used to titrate fluids in endotoxin-induced ARDS.
Assuntos
Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/fisiopatologia , Veia Cava Inferior/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Lipopolissacarídeos/toxicidade , Curva ROC , Ratos , Ratos Wistar , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Ultrassonografia , Veia Cava Inferior/diagnóstico por imagemRESUMO
Experimental studies have reported that aerobic exercise after asthma induction reduces lung inflammation and remodeling. Nevertheless, no experimental study has analyzed whether regular/moderate aerobic training before the induction of allergic asthma may prevent these inflammatory and remodeling processes. For this purpose, BALB/c mice (n = 96) were assigned into non-trained and trained groups. Trained animals ran on a motorized treadmill at moderate intensity, 30 min/day, 3 times/week, for 8 weeks, and were further randomized into subgroups to undergo ovalbumin sensitization and challenge or receive saline using the same protocol. Aerobic training continued until the last challenge. Twenty-four hours after challenge, compared to non-trained animals, trained mice exhibited: (a) increased systolic output and left ventricular mass on echocardiography; (b) improved lung mechanics; (c) decreased smooth muscle actin expression and collagen fiber content in airways and lung parenchyma; (d) decreased transforming growth factor (TGF)-ß levels in bronchoalveolar lavage fluid (BALF) and blood; (e) increased interferon (IFN)-γ in BALF and interleukin (IL)-10 in blood; and (f) decreased IL-4 and IL-13 in BALF. In conclusion, regular/moderate aerobic training prior to allergic asthma induction reduced inflammation and remodeling, perhaps through increased IL-10 and IFN-γ in tandem with decreased Th2 cytokines.
Assuntos
Remodelação das Vias Aéreas , Asma/imunologia , Citocinas/imunologia , Pulmão/imunologia , Condicionamento Físico Animal , Animais , Asma/induzido quimicamente , Líquido da Lavagem Broncoalveolar/imunologia , Imuno-Histoquímica , Inflamação , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-13/imunologia , Interleucina-4/imunologia , Pulmão/patologia , Pulmão/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Ovalbumina/efeitos adversos , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Pneumonia/patologia , Fator de Crescimento Transformador beta/imunologiaRESUMO
BACKGROUND AND PURPOSE: Asthma is characterized by chronic lung inflammation and airway hyperresponsiveness. Despite recent advances in understanding of its pathophysiology, asthma remains a major public health problem, and new therapeutic strategies are urgently needed. In this context, we sought to ascertain whether treatment with the TK inhibitor dasatinib might repair inflammatory and remodelling processes, thus improving lung function, in a murine model of asthma. EXPERIMENTAL APPROACH: Animals were sensitized and subsequently challenged, with ovalbumin (OVA) or saline. Twenty-four hours after the last challenge, animals were treated with dasatinib, dexamethasone, or saline, every 12 h for 7 consecutive days. Twenty-four hours after the last treatment, the animals were killed, and data were collected. Lung structure and remodelling were evaluated by morphometric analysis, immunohistochemistry, and transmission electron microscopy of lung sections. Inflammation was assessed by cytometric analysis and ELISA, and lung function was evaluated by invasive whole-body plethysmography. KEY RESULTS: In OVA mice, dasatinib, and dexamethasone led to significant reductions in airway hyperresponsiveness. Dasatinib was also able to attenuate alveolar collapse, contraction index, and collagen fibre deposition, as well as increasing elastic fibre content, in OVA mice. Concerning the inflammatory process, dasatinib reduced inflammatory cell influx to the airway and lung-draining mediastinal lymph nodes, without inducing the thymic atrophy promoted by dexamethasone. CONCLUSIONS AND IMPLICATIONS: In this model of allergic asthma, dasatinib effectively blunted the inflammatory and remodelling processes in asthmatic lungs, enhancing airway repair and thus improving lung mechanics.
Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Asma/tratamento farmacológico , Dasatinibe/farmacologia , Pulmão/efeitos dos fármacos , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Asma/imunologia , Asma/patologia , Asma/fisiopatologia , Dasatinibe/uso terapêutico , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Feminino , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/fisiopatologia , Pulmão/patologia , Pulmão/fisiopatologia , Camundongos Endogâmicos BALB C , Ovalbumina/imunologiaRESUMO
BACKGROUND AND PURPOSE: A long-term imbalance between pro- and anti-inflammatory mediators leads to airway remodelling, which is strongly correlated to most of the symptoms, severity and progression of chronic lung inflammation. The Angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis of the renin-angiotensin system is associated with attenuation of acute and chronic inflammatory processes. In this study, we investigated the effects of Ang-(1-7) treatment in a model of chronic allergic lung inflammation. EXPERIMENTAL APPROACH: Mice were sensitized to ovalbumin (OVA; 4 injections over 42 days, 14 days apart) and were challenged three times per week (days 21-46). These mice received Ang-(1-7) (1 µg·h(-1) , s.c.) by osmotic mini-pumps, for the last 28 days. Histology and morphometric analysis were performed in left lung and right ventricle. Airway responsiveness to methacholine, analysis of Ang-(1-7) levels (RIA), collagen I and III (qRT-PCR), ERK1/2 and JNK (Western blotting), IgE (elisa), cytokines and chemokines (elisa multiplex), and immunohistochemistry for Mas receptors were performed. KEY RESULTS: Infusion of Ang-(1-7) in OVA-sensitized and challenged mice decreased inflammatory cell infiltration and collagen deposition in the airways and lung parenchyma, and prevented bronchial hyperresponsiveness. These effects were accompanied by decreased IgE and ERK1/2 phosphorylation, and decreased pro-inflammatory cytokines. Mas receptors were detected in the epithelium and bronchial smooth muscle, suggesting a site in the lung for the beneficial actions of Ang-(1-7). CONCLUSIONS AND IMPLICATIONS: Ang-(1-7) exerted beneficial attenuation of three major features of chronic asthma: lung inflammation, airway remodelling and hyperresponsiveness. Our results support an important protective role of Ang-(1-7) in lung inflammation.
Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Angiotensina I/farmacologia , Anti-Inflamatórios/farmacologia , Hiper-Reatividade Brônquica/prevenção & controle , Broncoconstrição/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Pneumonia/prevenção & controle , Hipersensibilidade Respiratória/prevenção & controle , Animais , Hiper-Reatividade Brônquica/induzido quimicamente , Hiper-Reatividade Brônquica/metabolismo , Hiper-Reatividade Brônquica/fisiopatologia , Colágeno/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Hipertrofia Ventricular Direita/induzido quimicamente , Hipertrofia Ventricular Direita/fisiopatologia , Hipertrofia Ventricular Direita/prevenção & controle , Imunoglobulina E/sangue , Mediadores da Inflamação/metabolismo , Pulmão/metabolismo , Pulmão/fisiopatologia , Masculino , Camundongos Endogâmicos BALB C , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Ovalbumina , Fosforilação , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/agonistas , Proteínas Proto-Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Hipersensibilidade Respiratória/induzido quimicamente , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/fisiopatologia , Transdução de Sinais/efeitos dos fármacosRESUMO
We investigated the effects of acute hypercapnic acidosis and buffered hypercapnia on lung inflammation and apoptosis in experimental acute lung injury (ALI). Twenty-four hours after paraquat injection, 28 Wistar rats were randomized into four groups (n=7/group): (1) normocapnia (NC, PaCO2=35-45 mmHg), ventilated with 0.03%CO2+21%O2+balancedN2; (2) hypercapnic acidosis (HC, PaCO2=60-70 mmHg), ventilated with 5%CO2+21%O2+balancedN2; and (3) buffered hypercapnic acidosis (BHC), ventilated with 5%CO2+21%O2+balancedN2 and treated with sodium bicarbonate (8.4%). The remaining seven animals were not mechanically ventilated (NV). The mRNA expression of interleukin (IL)-6 (p=0.003), IL-1ß (p<0.001), and type III procollagen (PCIII) (p=0.001) in lung tissue was more reduced in the HC group in comparison with NC, with no significant differences between HC and BHC. Lung and kidney cell apoptosis was reduced in HC and BHC in comparison with NC and NV. In conclusion, in this experimental ALI model, hypercapnia, regardless of acidosis, reduced lung inflammation and lung and kidney cell apoptosis.
Assuntos
Acidose , Lesão Pulmonar Aguda/fisiopatologia , Apoptose , Hipercapnia , Pneumonia/fisiopatologia , Doença Aguda , Animais , Soluções Tampão , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Marcação In Situ das Extremidades Cortadas , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We evaluated whether isoflurane, halothane and sevoflurane attenuate the inflammatory response and improve lung morphofunction in experimental asthma. Fifty-six BALB/c mice were sensitised and challenged with ovalbumin and anaesthetised with isoflurane, halothane, sevoflurane or pentobarbital sodium for one hour. Lung mechanics and histology were evaluated. Gene expression of pro-inflammatory (tumour necrosis factor-α), pro-fibrogenic (transforming growth factor-ß) and pro-angiogenic (vascular endothelial growth factor) mediators, as well as oxidative process modulators, were analysed. These modulators included nuclear factor erythroid-2 related factor 2, sirtuin, catalase and glutathione peroxidase. Isoflurane, halothane and sevoflurane reduced airway resistance, static lung elastance and atelectasis when compared with pentobarbital sodium. Sevoflurane minimised bronchoconstriction and cell infiltration, and decreased tumour necrosis factor-α, transforming growth factor-ß, vascular endothelial growth factor, sirtuin, catalase and glutathione peroxidase, while increasing nuclear factor erythroid-2-related factor 2 expression. Sevoflurane down-regulated inflammatory, fibrogenic and angiogenic mediators, and modulated oxidant-antioxidant imbalance, improving lung function in this model of asthma.
Assuntos
Anestésicos Inalatórios/uso terapêutico , Asma/tratamento farmacológico , Anestésicos Inalatórios/farmacologia , Animais , Asma/fisiopatologia , Broncoconstrição/efeitos dos fármacos , Pulmão/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Recent data show an alarming increasing trend in obesity around the world. Mechanical ventilation in this population requires specific ventilatory settings due to the mechanical and inflammatory alterations observed in obesity. In this line, end-expiratory lung volume is decreased, leading to impairment in the mechanics of the respiratory system, lung and chest wall as well as gas-exchange. Furthermore, the inflammatory process acts on distal airways, increasing airway responsiveness, or on pulmonary endothelium cells, increasing the molecules related to the adherence of inflammatory cells. In order to reduce lung stress and strain, as well as minimize the risk of ventilator associated lung injury, mechanical ventilation management should be conducted with the following strategies: 1) stepwise recruitment maneuver before positive end-expiratory pressure application, which requires titration according to respiratory system dynamic compliance; and 2) tidal volume (VT) titration according to inspiratory capacity. In summary, the overall objective is to ensure an adequate setting of ventilator parameters in order to minimize the inflammatory impact already present in obese patients as well as prevent further lung damage.
Assuntos
Obesidade/fisiopatologia , Respiração Artificial/métodos , Fenômenos Biomecânicos , Humanos , Obesidade/complicações , Obesidade/patologia , Consumo de Oxigênio/fisiologia , Respiração com Pressão Positiva , Volume de Ventilação Pulmonar/fisiologiaRESUMO
Gene therapy is an alternative treatment for genetic lung disease, especially monogenic disorders such as cystic fibrosis. Cystic fibrosis is a severe autosomal recessive disease affecting one in 2500 live births in the white population, caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR). The disease is classically characterized by pancreatic enzyme insufficiency, an increased concentration of chloride in sweat, and varying severity of chronic obstructive lung disease. Currently, the greatest challenge for gene therapy is finding an ideal vector to deliver the transgene (CFTR) to the affected organ (lung). Adeno-associated virus is the most promising viral vector system for the treatment of respiratory disease because it has natural tropism for airway epithelial cells and does not cause any human disease. This review focuses on the basic properties of adeno-associated virus and its use as a vector for cystic fibrosis gene therapy.