RESUMO
Acetylcholine (ACh), the neurotransmitter of the cholinergic system, regulates inflammation in several diseases including pulmonary diseases. ACh is also involved in a non-neuronal mechanism that modulates the innate immune response. Because inflammation and release of pro-inflammatory cytokines are involved in pulmonary emphysema, we hypothesized that vesicular acetylcholine transport protein (VAChT) deficiency, which leads to reduction in ACh release, can modulate lung inflammation in an experimental model of emphysema. Mice with genetical reduced expression of VAChT (VAChT KDHOM 70%) and wild-type mice (WT) received nasal instillation of 50 uL of porcine pancreatic elastase (PPE) or saline on day 0. Twenty-eight days after, animals were evaluated. Elastase instilled VAChT KDHOM mice presented an increase in macrophages, lymphocytes, and neutrophils in bronchoalveolar lavage fluid and MAC2-positive macrophages in lung tissue and peribronchovascular area that was comparable to that observed in WT mice. Conversely, elastase instilled VAChT KDHOM mice showed significantly larger number of NF-κB-positive cells and isoprostane staining in the peribronchovascular area when compared to elastase-instilled WT-mice. Moreover, elastase-instilled VAChT-deficient mice showed increased MCP-1 levels in the lungs. Other cytokines, extracellular matrix remodeling, alveolar enlargement, and lung function were not worse in elastase-instilled VAChT deficiency than in elastase-instilled WT-controls. These data suggest that decreased VAChT expression may contribute to the pathogenesis of emphysema, at least in part, through NF-κB activation, MCP-1, and oxidative stress pathways. This study highlights novel pathways involved in lung inflammation that may contribute to the development of chronic obstrutive lung disease (COPD) in cholinergic deficient individuals such as Alzheimer's disease patients.
Assuntos
Acetilcolina/deficiência , Enfisema/imunologia , Pneumonia/etiologia , Acetilcolina/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/metabolismo , Modelos Animais de Doenças , Enfisema/metabolismo , Inflamação/patologia , Pulmão/patologia , Macrófagos/metabolismo , Masculino , Camundongos , NF-kappa B/metabolismo , Neutrófilos/metabolismo , Elastase Pancreática/efeitos adversos , Elastase Pancreática/farmacologia , Pneumonia/fisiopatologia , Enfisema Pulmonar/metabolismo , Transdução de Sinais , Proteínas Vesiculares de Transporte de Acetilcolina/deficiência , Proteínas Vesiculares de Transporte de Acetilcolina/genética , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismoRESUMO
BACKGROUND: Eugenol, a common phenylpropanoid derivative found in different plant species, has well-described anti-inflammatory effects associated with the development of occupational hypersensitive asthma. Dehydrodieugenol, a dimeric eugenol derivative, exhibits anti-inflammatory and antioxidant activities and can be found in the Brazilian plant species Nectandra leucantha (Lauraceae). The biological effects of dehydrodieugenol on lung inflammation remain unclear. PURPOSE: This study aimed to investigate the effects of eugenol and dehydrodieugenol isolated from N. leucantha in an experimental model of asthma. METHODS: In the present work, the toxic effects of eugenol and dehydrodieugenol on RAW 264.7 cells and their oxidant and inflammatory effects before lipopolysaccharide (LPS) exposure were tested. Then, male BALB/c mice were sensitized with ovalbumin through a 29-day protocol and treated with vehicle, eugenol, dehydrodieugenol or dexamethasone for eight days beginning on the 22nd day until the end of the protocol. Lung function; the inflammatory profile; and the protein expression of ERK1/2, JNK, p38, VAChT, STAT3, and SOCS3 in the lung were evaluated by immunoblotting. RESULTS: Eugenol and dehydrodieugenol were nontoxic to cells. Both compounds inhibited NO release and the gene expression of IL-1ß and IL-6 in LPS-stimulated RAW 264.7 cells. In OVA-sensitized animals, dehydrodieugenol reduced lung inflammatory cell numbers and the lung concentrations of IL-4, IL-13, IL-17, and IL-10. These anti-inflammatory effects were associated with inhibition of the JNK, p38 and ERK1/2, VAChT and STAT3/SOCS3 pathways. Moreover, treatment with dehydrodieugenol effectively attenuated airway hyperresponsiveness. CONCLUSION: The obtained data demonstrate, for the first time, that dehydrodieugenol was more effective than eugenol in counteracting allergic airway inflammation in mice, especially its inhibition of the JNK, p38 and ERK1/2, components of MAPK pathway. Therefore, dehydrodieugenol can be considered a prototype for the development of new and effective agents for the treatment of asthmatic patients.
Assuntos
Asma/tratamento farmacológico , Eugenol/análogos & derivados , Lignanas/uso terapêutico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pneumonia/tratamento farmacológico , Fator de Transcrição STAT3/antagonistas & inibidores , Proteína 3 Supressora da Sinalização de Citocinas/antagonistas & inibidores , Animais , Asma/metabolismo , Relação Dose-Resposta a Droga , Eugenol/isolamento & purificação , Eugenol/farmacologia , Eugenol/uso terapêutico , Lauraceae , Lignanas/isolamento & purificação , Lignanas/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Pneumonia/metabolismo , Células RAW 264.7 , Fator de Transcrição STAT3/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismoRESUMO
The cholinergic anti-inflammatory pathway has been shown to regulate lung inflammation and cytokine release in acute models of inflammation, mainly via α7 nicotinic receptor (α7nAChR). We aimed to evaluate the role of endogenous acetylcholine in chronic allergic airway inflammation in mice and the effects of therapeutic nAChR stimulation in this model. We first evaluated lung inflammation and remodeling on knock-down mice with 65% of vesicular acetylcholine transport (VAChT) gene reduction (KDVAChT) and wild-type(WT) controls that were subcutaneously sensitized and then inhaled with ovalbumin(OVA). We then evaluated the effects of PNU-282987(0.5-to-2mg/kg),(α7nAChR agonist) treatment in BALB/c male mice intraperitoneal sensitized and then inhaled with OVA. Another OVA-sensitized-group was treated with PNU-282987 plus Methyllycaconitine (MLA,1 mg/kg, α7nAChR antagonist) to confirm that the effects observed by PNU were due to α7nAChR. We showed that KDVAChT-OVA mice exhibit exacerbated airway inflammation when compared to WT-OVA mice. In BALB/c, PNU-282987 treatment reduced the number of eosinophils in the blood, BAL fluid, and around airways, and also decreased pulmonary levels of IL-4,IL-13,IL-17, and IgE in the serum of OVA-exposed mice. MLA pre-treatment abolished all the effects of PNU-282987. Additionally, we showed that PNU-282987 inhibited STAT3-phosphorylation and reduced SOCS3 expression in the lung. These data indicate that endogenous cholinergic tone is important to control allergic airway inflammation in a murine model. Moreover, α7nAChR is involved in the control of eosinophilic inflammation and airway remodeling, possibly via inhibition of STAT3/SOCS3 pathways. Together these data suggest that cholinergic anti-inflammatory system mainly α7nAChR should be further considered as a therapeutic target in asthma.
Assuntos
Asma/imunologia , Proteínas Vesiculares de Transporte de Acetilcolina/deficiência , Receptor Nicotínico de Acetilcolina alfa7/imunologia , Remodelação das Vias Aéreas , Alérgenos , Animais , Asma/etiologia , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Doença Crônica , Citocinas/imunologia , Modelos Animais de Doenças , Inflamação/etiologia , Inflamação/imunologia , Contagem de Leucócitos , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Knockout , Ovalbumina , Fator de Transcrição STAT3/antagonistas & inibidores , Proteína 3 Supressora da Sinalização de Citocinas/antagonistas & inibidores , Proteínas Vesiculares de Transporte de Acetilcolina/genética , Receptor Nicotínico de Acetilcolina alfa7/agonistasRESUMO
Asthma allergic disease is caused by airway chronic inflammation. Some intracellular signaling pathways, such as MAPK and STAT3-SOCS3, are involved in the control of airway inflammation in asthma. The flavonoid sakuranetin demonstrated an anti-inflammatory effect in different asthma models. Our aim was to clarify how sakuranetin treatment affects MAPK and STAT3-SOCS3 pathways in a murine experimental asthma model. Mice were submitted to an asthma ovalbumin-induction protocol and were treated with vehicle, sakuranetin, or dexamethasone. We assayed the inflammatory profile, mucus production, and serum antibody, STAT3-SOCS3, and MAPK levels in the lungs. Morphological alterations were also evaluated in the liver. LPS-stimulated RAW 264.7 cells were used to evaluate the effects of sakuranetin on nitric oxide (NO) and cytokine production. In vivo, sakuranetin treatment reduced serum IgE levels, lung inflammation (eosinophils, neutrophils, and Th2/Th17 cytokines), and respiratory epithelial mucus production in ovalbumin-sensitized animals. Considering possible mechanisms, sakuranetin inhibits the activation of ERK1/2, JNK, p38, and STAT3 in the lungs. No alterations were found in the liver for treated animals. Sakuranetin did not modify in vitro cell viability in RAW 264.7 and reduced NO release and gene expression of IL-1ß and IL-6 induced by LPS in these cells. In conclusion, our data showed that the inhibitory effects of sakuranetin on eosinophilic lung inflammation can be due to the inhibition of Th2 and Th17 cytokines and the inhibition of MAPK and STAT3 pathways, reinforcing the idea that sakuranetin can be considered a relevant candidate for the treatment of inflammatory allergic airway disease.
Assuntos
Flavonoides/uso terapêutico , Hipersensibilidade/tratamento farmacológico , Hipersensibilidade/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Extratos Vegetais/uso terapêutico , Fator de Transcrição STAT3/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Animais , Western Blotting , Citocinas/metabolismo , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7RESUMO
Sakuranetin is the main isolate flavonoid from Baccharis retusa (Asteraceae) leaves and exhibits anti-inflammatory and antioxidative activities. Acute respiratory distress syndrome is an acute failure of the respiratory system for which effective treatment is urgently necessary. This study investigated the preventive and therapeutic effects of sakuranetin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Animals were treated with intranasal sakuranetin 30 min before or 6 h after instillation of LPS. Twenty-four hours after ALI was induced, lung function, inflammation, macrophages population markers, collagen fiber deposition, the extent of oxidative stress, and the expression of matrix metalloprotease-9 (MMP-9), tissue inhibitor of MMP-9 (TIMP-1) and NF-κB were evaluated. The animals began to show lung alterations 6 h after LPS instillation, and these changes persisted until 24 h after LPS administration. Preventive and therapeutic treatment with sakuranetin reduced the neutrophils in the peripheral blood and in the bronchial alveolar lavage. Sakuranetin treatment also reduced macrophage populations, particularly that of M1-like macrophages. In addition, sakurnaetin treatment reduced keratinocyte-derived chemokines (IL-8 homolog) and NF-κB levels, collagen fiber formation, MMM-9 and TIMP-1-positive cells, and oxidative stress in lung tissues compared with LPS animals treated with vehicle. Finally, sakuranetin treatment also reduced total protein, and the levels of TNF-α and IL-1ß in the lung. This study shows that sakuranetin prevented and reduced pulmonary inflammation induced by LPS. Because sakuranetin modulates oxidative stress, the NF-κB pathway, and lung function, it may constitute a novel therapeutic candidate to prevent and treat ALI.
Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/prevenção & controle , Flavonoides/uso terapêutico , Lesão Pulmonar Aguda/sangue , Lesão Pulmonar Aguda/complicações , Animais , Biomarcadores/metabolismo , Polaridade Celular/efeitos dos fármacos , Colágeno/metabolismo , Complacência (Medida de Distensibilidade)/efeitos dos fármacos , Citocinas/metabolismo , Flavonoides/química , Flavonoides/farmacologia , Mediadores da Inflamação/metabolismo , Leucócitos/efeitos dos fármacos , Lipopolissacarídeos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Pneumonia/sangue , Pneumonia/complicações , Pneumonia/tratamento farmacológico , Pneumonia/fisiopatologia , Subunidades Proteicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Fator de Transcrição RelA/metabolismoRESUMO
Nicotinic α-7 acetylcholine receptor (nAChRα7) is a critical regulator of cholinergic anti-inflammatory actions in several diseases, including acute respiratory distress syndrome (ARDS). Given the potential importance of α7nAChR as a therapeutic target, we evaluated whether PNU-282987, an α7nAChR agonist, is effective in protecting the lung against inflammation. We performed intratracheal instillation of LPS to generate acute lung injury (ALI) in C57BL/6 mice. PNU-282987 treatment, either before or after ALI induction, reduced neutrophil recruitment and IL-1ß, TNF-α, IL-6, keratinocyte chemoattractant (KC), and IL-10 cytokine levels in the bronchoalveolar lavage fluid (P < 0.05). In addition, lung NF-κB phosphorylation decreased, along with collagen fiber deposition and the number of matrix metalloproteinase-9+ and -2+ cells, whereas the number of tissue inhibitor of metalloproteinase-1+ cells increased (P < 0.05). PNU-282987 treatment also reduced lung mRNA levels and the frequency of M1 macrophages, whereas cells expressing the M2-related markers CD206 and IL-10 increased, suggesting changes in the macrophage profile. Finally, PNU-282987 improved lung function in LPS-treated animals. The collective results suggest that PNU-282987, an agonist of α7nAChR, reduces LPS-induced experimental ALI, thus supporting the notion that drugs that act on α7nAChRs should be explored for ARDS treatment in humans.-Pinheiro, N. M., Santana, F. P. R., Almeida, R. R., Guerreiro, M., Martins, M. A., Caperuto, L. C., Câmara, N. O. S., Wensing, L. A., Prado, V. F., Tibério, I. F. L. C., Prado, M. A. M., Prado, C. M. Acute lung injury is reduced by the α7nAChR agonist PNU-282987 through changes in the macrophage profile.
Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Benzamidas/uso terapêutico , Compostos Bicíclicos com Pontes/uso terapêutico , Lipopolissacarídeos/toxicidade , Macrófagos/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Animais , Líquido da Lavagem Broncoalveolar , Citocinas/genética , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/metabolismo , Masculino , Camundongos , RNA/genética , RNA/metabolismoRESUMO
Despite its common use, the synthetic glucocorticoid dexamethasone can cause several adverse effects, such as diabetes and insulin-related metabolic impairment. Thus, research on molecules that could provide the same anti-inflammatory response with milder side effects is constant. In this work the anti-inflammatory activity of the natural sesquiterpene polygodial, extracted from the endemic Brazilian plant Drimys brasiliensis Miers (Winteraceae), was investigated. Employing a pancreatic ß-cell model (INS 1E), the effect of polygodial on signaling pathways is similar to that caused by dexamethasone - both increased MKP1 and decreased ERK1/2 expression in a dose-response and time-dependent manner. Relating to such finding, nuclear translocation of the glucocorticoid receptor was also discovered to be induced by the sesquiterpene. Molecular modeling results indicated that polygodial was capable of docking to the glucocorticoid receptor, but presented preference for the Arg611 binding site rather than Thr739 when set to bind freely inside the pocket. At last, fragmentation of DNA was verified as consequence of sesquiterpene-induced cell death. Altogether, our results suggest that, like dexamethasone, polygodial interacts the glucocorticoid receptor ligand binding domain but create fewer ligand-protein interactions at the site, yielding a weaker effector response. Such property provides an advantage when regarding the adverse effects resulting from stronger affinity ligands of the glucocorticoid receptor, such as in the case of the current standard dexamethasone-based treatment. This aspect, also, turns polygodial an interesting hit compound to the development of new drugs based on its backbone structure providing less harmful anti-inflammatory treatments.
Assuntos
Dexametasona/farmacologia , Drimys/química , Glucocorticoides/farmacologia , Células Secretoras de Insulina/metabolismo , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Dexametasona/química , Células Secretoras de Insulina/efeitos dos fármacos , Camundongos , Simulação de Acoplamento Molecular , Transporte Proteico/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismo , Sesquiterpenos/química , Transdução de Sinais/efeitos dos fármacos , Fatores de TempoRESUMO
BACKGROUND: Pulmonary emphysema is characterized by irreversible airflow obstruction, inflammation, oxidative stress imbalance and lung remodeling, resulting in reduced lung function and a lower quality of life. Flavonoids are plant compounds with potential anti-inflammatory and antioxidant effects that have been used in folk medicine. Our aim was to determine whether treatment with sakuranetin, a flavonoid extracted from the aerial parts of Baccharis retusa, interferes with the development of lung emphysema. METHODS: Intranasal saline or elastase was administered to mice; the animals were then treated with sakuranetin or vehicle 2 h later and again on days 7, 14 and 28. We evaluated lung function and the inflammatory profile in bronchoalveolar lavage fluid (BALF). The lungs were removed to evaluate alveolar enlargement, extracellular matrix fibers and the expression of MMP-9, MMP-12, TIMP-1, 8-iso-PGF-2α and p65-NF-κB in the fixed tissues as well as to evaluate cytokine levels and p65-NF-κB protein expression. RESULTS: In the elastase-treated animals, sakuranetin treatment reduced the alveolar enlargement, collagen and elastic fiber deposition and the number of MMP-9- and MMP-12-positive cells but increased TIMP-1 expression. In addition, sakuranetin treatment decreased the inflammation and the levels of TNF-α, IL-1ß and M-CSF in the BALF as well as the levels of NF-κB and 8-iso-PGF-2α in the lungs of the elastase-treated animals. However, this treatment did not affect the changes in lung function. CONCLUSION: These data emphasize the importance of oxidative stress and metalloproteinase imbalance in the development of emphysema and suggest that sakuranetin is a potent candidate that should be further investigated as an emphysema treatment. This compound may be useful for counteracting lung remodeling and oxidative stress and thus attenuating the development of emphysema.
Assuntos
Baccharis , Flavonoides/uso terapêutico , Metaloproteinases da Matriz/biossíntese , NF-kappa B/metabolismo , Estresse Oxidativo/fisiologia , Enfisema Pulmonar/metabolismo , Animais , Flavanonas/isolamento & purificação , Flavanonas/uso terapêutico , Flavonoides/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Elastase Pancreática/toxicidade , Componentes Aéreos da Planta , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/prevenção & controle , SuínosRESUMO
Acetylcholine (ACh) plays a crucial role in physiological responses of both the central and the peripheral nervous system. Moreover, ACh was described as an anti-inflammatory mediator involved in the suppression of exacerbated innate response and cytokine release in various organs. However, the specific contributions of endogenous release ACh for inflammatory responses in the lung are not well understood. To address this question we have used mice with reduced levels of the vesicular acetylcholine transporter (VAChT), a protein required for ACh storage in secretory vesicles. VAChT deficiency induced airway inflammation with enhanced TNF-α and IL-4 content, but not IL-6, IL-13 and IL-10 quantified by ELISA. Mice with decreased levels of VAChT presented increased collagen and elastic fibers deposition in airway walls which was consistent with an increase in inflammatory cells positive to MMP-9 and TIMP-1 in the lung. In vivo lung function evaluation showed airway hyperresponsiveness to methacholine in mutant mice. The expression of nuclear factor-kappa B (p65-NF-kB) in lung of VAChT-deficient mice were higher than in wild-type mice, whereas a decreased expression of janus-kinase 2 (JAK2) was observed in the lung of mutant animals. Our findings show the first evidence that cholinergic deficiency impaired lung function and produce local inflammation. Our data supports the notion that cholinergic system modulates airway inflammation by modulation of JAK2 and NF-kB pathway. We proposed that intact cholinergic pathway is necessary to maintain the lung homeostasis.