Attenuation of airway inflammation by simvastatin and the implications for asthma treatment: is the jury still out?

Although some studies have explained the immunomodulatory effects of statins, the exact mechanisms and the therapeutic significance of these molecules remain to be elucidated. This study not only evaluated the therapeutic potential and inhibitory mechanism of simvastatin in an ovalbumin (OVA)-specific asthma model in mice but also sought to clarify the future directions indicated by previous studies through a thorough review of the literature. BALB/c mice were sensitized to OVA and then administered three OVA challenges. On each challenge day, 40 mg kg-1 simvastatin was injected before the challenge. The airway responsiveness, inflammatory cell composition, and cytokine levels in bronchoalveolar lavage (BAL) fluid were assessed after the final challenge, and the T cell composition and adhesion molecule expression in lung homogenates were determined. The administration of simvastatin decreased the airway responsiveness, the number of airway inflammatory cells, and the interleukin (IL)-4, IL-5 and IL-13 concentrations in BAL fluid compared with vehicle-treated mice (P<0.05). Histologically, the number of inflammatory cells and mucus-containing goblet cells in lung tissues also decreased in the simvastatin-treated mice. Flow cytometry showed that simvastatin treatment significantly reduced the percentage of pulmonary CD4+ cells and the CD4+/CD8+ T-cell ratio (P<0.05). Simvastatin treatment also decreased the expression of the vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 proteins, as measured in homogenized lung tissues (P<0.05) and human epithelial cells. The reduction in the T cell influx as a result of the decreased expression of cell adhesion molecules is one of the mechanisms by which simvastatin attenuates airway responsiveness and allergic inflammation. Rigorous review of the literature together with our findings suggested that simvastatin should be further developed as a potential therapeutic strategy for allergic asthma.

Immunomodulatory effects of astragalus gypsicolus hydroalcoholic extract in ovalbumin-induced allergic mice model

Several studies have demonstrated that herbal extracts possess various biological effects including anti-inflammatory and anti-cancer activities. The present study was aimed to investigate the protective effects of the Astragalus gypsicolus [AG] hydroalcoholic extract in early allergic sensitized mice induced by ovalbumin. Phytochemical assay was used to recognize the main active constituents in the AG hydroalcoholic extract. Mice were immunized with subcutaneous injection of ovalbumin and aluminum hydroxide. Efficiency of sensitization was assessed by serum IgE levels and eosinophil count. After sensitization, two doses of extract [250 mg/kg and 500 mg/kg] were injected intrapritoneally. On day 14, mice were challenged with intrapritoneal injection of ovalbumin. IL-4 and IFN gamma levels in broncoalveolar lavage fluid, which had been collected on day 15, were assessed by Enzyme-Linked Immunosorbent Assay [ELISA] kit. Our results indicate two main active constituents including flavonoids and terpenoids are present in the AG.hydroalcoholic extract. Intrapritoneal injection of the AG hydroalcoholic extract was able to decrease IL-4 and increase IFN gamma. It seems the AG hydroalcoholic extract has the potential to modulate the balance of Thl/Th2 cytokines in allergy

Mast cells play a key role in Th2 cytokine-dependent asthma model through production of adhesion molecules by liberation of TNF-alpha

Mast cells are well recognized as key cells in allergic reactions, such as asthma and allergic airway diseases. However, the effects of mast cells and TNF-alpha on T-helper type 2 (Th2) cytokine-dependent asthma are not clearly understood. Therefore, an aim of this study was to investigate the role of mast cells on Th2 cytokine-dependent airway hyperresponsiveness and inflammation. We used genetically mast cell-deficient WBB6F1/J-KitW/KitW-v (W/Wv), congenic normal WBB6F1/J-Kit+/Kit+ (+/+), and mast cell-reconstituted W/Wv mouse models of allergic asthma to investigate the role of mast cells in Th2 cytokine-dependent asthma induced by ovalbumin (OVA). And we investigated whether the intratracheal injection of TNF-alpha directly induce the expression of ICAM-1 and VCAM-1 in W/Wv mice. This study, with OVA-sensitized and OVA-challenged mice, revealed the following typical histopathologic features of allergic diseases: increased inflammatory cells of the airway, airway hyperresponsiveness, and increased levels of TNF-alpha, intercellular adhesion molecule (ICAM)-1, and vascular cellular adhesion molecule (VCAM)-1. However, the histopathologic features and levels of ICAM-1 and VCAM-1 proteins in W/Wv mice after OVA challenges were significantly inhibited. Moreover, mast cell-reconstituted W/Wv mice showed restoration of histopathologic features and recovery of ICAM-1 and VCAM-1 protein levels that were similar to those found in +/+ mice. Intratracheal administration of TNF-alpha resulted in increased ICAM-1 and VCAM-1 protein levels in W/Wv mice. These results suggest that mast cells play a key role in a Th2 cytokine-dependent asthma model through production of adhesion molecules, including ICAM-1 and VCAM-1, by liberation of TNF-alpha.

The Soluble Tumor Necrosis Factor-Alpha Receptor Suppresses Airway Inflammation in a Murine Model of Acute Asthma

PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that has been implicated in many aspects of the airway pathology in asthma. TNF-alpha blocking strategies are now being tried in asthma patients. This study investigated whether TNF-alpha blocking therapy inhibits airway inflammation and airway hyperresponsiveness (AHR) in a mouse model of asthma. We also evaluated the effect of TNF-alpha blocking therapy on cytokine production and adhesion molecule expression. MATERIALS AND METHODS: Ovalbumin (OVA) sensitized BALB/c female mice were exposed to intranasal OVA administration on days 31, 33, 35, and 37. Mice were treated intraperitoneally with soluble TNF-alpha receptor (sTNFR) during the OVA challenge. RESULTS: There were statistically significant decreases in the numbers of total cell and eosinophil in bronchoalveolar lavage fluid (BALF) in the sTNFR treated group compared with the OVA group. However, sTNFR-treatment did not significantly decrease AHR. Anti-inflammatory effect of sTNFR was accompanied with reduction of T helper 2 cytokine levels including interleukin (IL)-4, IL-5 and IL-13 in BALF and vascular cell adhesion molecule 1 expression in lung tissue. CONCLUSION: These results suggest that sTNFR treatment can suppress the airway inflammation via regulation of Th2 cytokine production and adhesion molecule expression in bronchial asthma.

The Effect of CpG-Oligodeoxynucleotides with Different Backbone Structures and 3' Hexameric Deoxyriboguanosine Run Conjugation on the Treatment of Asthma in Mice

CpG-Oligodeoxynucleotide (ODN) has two backbones. Phosphorothioate backbone (PS) shows a strong immunostimulating effect while phosphodiester (PE) shows little in vivo. 3' hexameric deoxyriboguanosine-run (3' dG6-run) conjugation to PE CpG-ODN has been reported to enhance immunostimulation and to protect against asthma when injected at the time of sensitization in mice. We evaluated the treatment effects of PE and PS CpG-ODN with or without 3' dG6-run on asthma in presensitized mice. BALB/c mice sensitized with ovalbumin and alum were challenged with 1% ovalbumin on three days. CpG-ODNs (100 microgram) or PBS were injected 4 times; 27 hr before challenge and 3 hr before each challenge (CpG-dG6: CpG-ODN with 3' dG6-run, PE*-CpG-dG6: PE-CpG-dG6 with two PS backbones at the 5' terminus). PE-CpG showed no treatment effect. PE-CpG-dG6 only increased ovalbumin-specific IgG2a. PE*-CpG-dG6 increased ovalbumin-specific IgG2a but also reduced BAL fluid eosinophils and airway hyperresponsiveness. PS-CpG increased ovalbumin-specific IgG2a, reduced airway inflammation and airway hyperresponsiveness. PS-CpG-dG6 was less effective than PS-CpG on airway inflammation and airway hyperresponsiveness. In pre-sensitized mice, PE-CpG required not only 3' dG6-run but also the modification of two PS linkages at 5' terminus to inhibit features of asthma. PS-CpG was strong enough to inhibit asthma but PS-CpG-dG6 was less effective.

TNF-a and IL-10 levels in tracheobronchial lavage of ventilated preterm infants and subsequent lung function

The role of airway inflammation in ventilated preterm newborns and the risk factors associated with the development of chronic lung disease are not well understood. Our objective was to analyze the association of the airway inflammatory response in ventilated preterm infants by serial measurements of TNF-a and IL-10 in tracheobronchial lavage (TBL) with perinatal factors and lung function measured early in life. A series of TBL samples were collected from ventilated preterm infants (less than 32 weeks of gestational age) and concentrations of TNF-a and IL-10 were measured by ELISA. Pulmonary function tests were performed after discharge by the raised volume rapid compression technique. Twenty-five subjects were recruited and 70 TBL samples were obtained. There was a significant positive association between TNF-a and IL-10 levels and length of time between the rupture of the amniotic membranes and delivery (r = 0.65, P = 0.002, and r = 0.57, P < 0.001, respectively). Lung function was measured between 1 and 22 weeks of corrected age in 10 patients. Multivariable analysis with adjustment for differences in lung volume showed a significant negative association between TNF-a levels and forced expiratory flow (FEF50; r = -0.6; P = 0.04), FEF75 (r = -0.76; P = 0.02), FEF85 (r = -0.75; P = 0.03), FEF25-75 (-0.71; P = 0.02), and FEV0.5 (r = -0.39; P = 0.03). These data suggest that TNF-a levels in the airways during the first days of life were associated with subsequent lung function abnormalities measured weeks or months later.

Inflammatory cytokine levels in induced sputum and bronchoalveolar lavage fluid in pulmonary sarcoidosis.

BACKGROUND: The immune inflammatory process in patients with sarcoidosis is not only compartmentalized within the alveolar walls, but also involves the bronchial airways. Analysis of induced sputum has been used as a non-invasive tool for investigating the airways and may reflect the endobronchial and parenchymal inflammation in patients with sarcoidosis. This present study was designed to measure the soluble pro-inflammatory cytokine levels interleukin-1 (IL-1), interleukin-6 (IL-6), tumuor necrosis factor-alpha (TNF-alpha) and percentage of macrophages expressing these cytokines in induced sputum and bronchoalveolar lavage (BAL) fluid in patients with pulmonary sarcoidosis. METHODS: Sputum induction and BAL was carried out in 27 patients with newly diagnosed sarcoidosis. Control group consisted of six patients with a normal chest radiograph (three patients with carcinoma esophagus and three patients with doubtful history of hemoptysis). Induced sputum was also obtained from 10 non-smoking, non-atopic healthy controls. RESULTS: Percentage of macrophages expressing pro-inflammatory cytokines and soluble cytokine levels in induced sputum were higher in patients with sarcoidosis compared to both groups of controls. There was good correlation between IL-6 and TNF-alpha levels (r = 0.49, 0.58 p < 0.05) and percentage of macrophages expressing all three cytokines (r = 0.56-0.71, p < 0.01) between induced sputum and BAL fluid. Mild positive correlation between cytokine levels in sputum and age was also noted (r = 0.33-0.38, p < 0.05). CONCLUSIONS: Induced sputum may reflect changes in cytokine milieu in BAL in sarcoidosis.

Study of Interleukin-16 in Bronchoalveolar lavage of Smokers with and without chronic bronchitis

The study included 30 subjects [10 case of healthy smokers with no chest symptoms, 10 cases of smokers with chronic bronchitis and ten healthy non smokers as control group]. The result of this study showed highly significant statistical increase in the level of IL- 16 in BAL and serum of smokers with or without chronic bronchitis compared to control group [P < 0.001, P < 0.0001 respectively] but no significant statistical difference in its level in BAL and serum of smokers with and without chronic bronchitis [P < 0.05, P > 0.05 respectively]. Also, there was no significant correlation between serum and BAL IL- 16 level in non smokers and smokers without chronic bronchitis [P< 0.05] but there was a significant correlation between them in smokers with chronic bronchitis [P< 0.05]. We concluded that, BAL and serum IL- 16 levels are significantly higher in smokers, [even if they are asymptomatic] than in non smokers, this fact must make us to focus on the danger of smoking in the community

Efecto antiinflamatorio del líquido amniótico en el pulmón de ratas inoculadas intratraquealmente con sílice / Antiinflamatory efect of amniotic fluid in the lung of ratas intratracheally inoculated with silica

El síndrome de aspiración de meconio representa un estado patológico de gran importancia para la medicina humana; sin embargo, es poco conocido en medicina veterinaria. En los últimos años se han realizado varias investigaciones con el fin de esclarecer la importancia y patogénesis de este síndrome en los animales domésticos. Estudios recientes han surgido un posible efecto antiinflamatorio del líquido amniótico debido a que la aspiración de este líquido contaminado con queratina, la cual es un factor proinflamatorio, sólo induce una respuesta inflamatoria leve en el pulmón de becerros. El objetivo de esta investigación fue determinar si el líquido amniótico produce un efecto antiinflamatorio en los pulmones de ratas inoculadas intratraquealmente con sílice. Treinta y ocho ratas Wistar de 177 g en promedio se dividieron en cinco grupos. Cada grupos recibió vía intratraqueal diferentes dosis de líquido amniótico y solución salina fisiológica (0, 0.125, 0.250, 0.375 y 0.5 ml, respectivamente) y cantidades constantes de sílice (5 mg/ml). Los animales inoculados se sacrificaron a las 72 horas posinoculación y se realizaron lavados broncoalveolares. Se realizó la cuenta total de células nucleadas por ml de lavado, así como el porcentaje y cuenta absoluta de neutrófilos y macró fagos. La inoculación con sílice y líquido amniótico indujo un marcado incremento en la cuenta total de células nucleadas y en el número de neutrófilos (P < 0.01) en los grupos tratados respecto del testigo. El incremento se mostró como una función directa del volumen de líquido amniótico inoculado. Sin embargo, se concluyó que el líquido amniótico no tuvo un efecto antiinflamatorio en el pulmón de ratas inoculadas intratraquealmente con sílice

Estudio comparativo de la IgA secretora / Comparative study of secretor IgA

Objetivo: medir y comparar los niveles de IgA secretora (SIGA) en la mucosa del árbol respiratorio. Diseño: estudio transversal descriptivo. Lugar de realización: Departamento de Neumología, Hospital General del CMN L Raza, IMSS. Material y métodos: se incluyeron 35 sujetos voluntarios con consentimiento informado para someterse a lavado nasal y lavado bronquial, cuyas mustras junto con la expectoración se analizaron para determinar niveles de SIgA por el método nefelométrico, reportándose como la concentración relativa de SIgA/concentración entre los tres tipos de muestras. Resultados: los valores de SIgA en expectoración, lavado nasofaríngeo y lavado bronquial fueron similares. La media y error estándar a nivel nosofaríngeo fue 0.ñ064 0.007, a nivel de esputo 0.073 ñ 0.01 y a nivel bronquial 0. 082 ñ 0.017. La correlación obtuvo r= 0.508 (p < 0.01)

Cunatificación de la SIgA en pacientes con bronquitis crónica estable / Quantification of the secretory IgA in patients with acute bronchitis

Basados en el hecho de la importancia de la inmunología de las mucosas y del papel que juega la IgA secretora en el aparato respiratorio y ante el hecho de la carencia de datos al respecto en población bronquítica crónica se realizó un estudio clínico porspectivo y transversal en 100 pacientes, mismos que se dividieron en dos grupos: 50 pacientes sanos y 50 con bronquitis crónica estable. a todos ellos se les diagnósticó con los estándares para confirmación y se recolectó la muestra a través de lavado nasal en los pacientes sanos y por expectoración en los bronquítico-crónicos. Se estudiaron por nefelometría por rayos láser. Las concentraciones de IgA se expresaron como resultado de dividir la concentración de IgA entre la concentración total de proteínas de la muestra. El análisis se efectuó por medio de la t de Student. Los resultados demostraron un ligero incremento no significativo a favor de los pacientes bronquítico crónicos. se concluye que tal incremento se deve a un estado de estimulación continua de las mucosas lo que eleva la concentración de IgA como un mecaismo de defensa

Avaliaçäo do estado funcional dos macrófagos alveolares de ratos tratados com amiodarona / Evaluation of alveolar mascrophage functions of amiodarone treated rats

Embora a amiodarona seja um antiarrítmico efetivo, seu uso está associado a vários efeitos colaterais. Entre esses, o mais sério é a toxicidade pulmonar caracterizada por pneumonite intersticial e fibrose. A patogênese da toxicidade pulmonar näo está determinada. Contudo, o aspecto morfológico proeminente induzido pela amiodarona é a fosfolipidose. O efeito da fosfolipidose sobre as funçöes macrofágicas, permanece ainda obscuro. A hipótese levantada por este trabalho é que macrófagos alveolares de ratos tratados com amiodarona apresentam alteraçöes funcionais que contribuem para o aparecimento da pneumonite. Para testar esta hipótese, estudou-se o LBA e a histologia pulmonar em três linhagens de ratos (Wistar, Wistar-Kyoto e SHR), de ambos os sexos, avaliando a tipagem e quantificaçäo de células (Experimento 1). Em ratos machos da linhagem Wistar tratados com amiodarona, cujos macrófagos alveolares apresentaram acentuada fosfolipidose, estudou-se as funçöes macrofágicas básicas (espraiamento e liberaçäo de H2O2) e a expressäo de moléculas de adesäo (CD18 e e CD54) em sua superfície, por citometria de fluxo (Experimento 2). Os resultados destes experimentos mostraram que o uso da linhagem Wistar para estudo da intoxicaçäo por amiodarona é eficiente em simular como o modelo experimental, as alteraçöes na celularidade do LBA e a fosfolipidose pulmonar. A intoxicaçäo por amiodarona produzida em animais também apresenta predileçäo pelo sexo masculino. As linhages de ratos Wistar-Kyoto e SHR, apesar de serem isogênicas, näo servem como modelo de pneumonite por amiodarona devido à grande suceptibilidade à infecçöes e hemorragia. Os estudos funcionais dos macrófagos alveolares revelaram que estas células encontram-se ativadas durante todo o período de estudo. O pico de maior ativaçäo macrofágica ocorreu com seis semanas de tratamento com amiodarona, provavelmente por maior recrutamento de monócitos mostrado pelo aumento de expressäo das moléculas de adesäo. A fosfolipidose näo inibe as funçöes macrofágicas e, neste modelo, os macrófagos alveolares estäo ativados pelo amiodarona e/ou fosfolipidose, gerando uma resposta inflamatória após seis semanas do uso da droga; resposta esta näo mais observada na 12ª semana.

Monocyte/macrophage functions & humoral response in blood & bronchoalveolar lavage fluid of pulmonary tuberculosis patients.

Subsegmental bronchoalveolar lavage (BAL) was performed in 33 patients with active pulmonary tuberculosis and five control subjects. Phagocytosis by monocytes and alveolar macrophages was studied, and in addition serum and BAL immunoglobulin and complement levels were also determined. The phagocytic activity of blood monocytes was depressed in pulmonary tuberculosis patients as compared to controls, 37.8 +/- 2.3 per cent; 50.7 +/- 4.2 per cent and 32.9 +/- 3.6 per cent for sheep RBC's, latex and Staphylococcus aureus respectively compared to 66.7 +/- 6, 54.8 +/- 2.2 and 68.3 +/- 3.5 per cent respectively in controls; the differences being significant for sheep RBC's (P less than 0.05) and Staph. aureus (P less than 0.001). However, phagocytosis was not impaired in BAL macrophages (P greater than 0.05). In patients no significant alteration in serum immunoglobulin and complement levels was observed except that levels of C4 component of complement were increased in patients with far advanced lesions (98.5 +/- 33.7 mg/dl compared to 78.7 +/- 7.9 mg/dl; P less than 0.05). While IgM and C4 component of complement could not be detected in BAL fluid the levels of IgA were significantly increased in pulmonary tuberculosis patients (65.5 +/- 50.5 mg/dl compared to 39.9 +/- 13.3 mg/dl in control; P less than 0.05). Since IgA secreted in the BAL fluid is mostly synthesised locally, increased levels of this immunoglobulin could be of value in determining activity of the disease.

Involvement of eicosanoids and PAF in immune-coplex alveolitis

An immune-complex-mediated hypersensitivity reaction induced in the rat lung was followed by release of the eicosanoids thromboxane, prostaglandin E2 and leukotriene B4 into bronchoalveolar space. Concomitantly, there was a decrease in the number of circulating platelets. The thrombocytopenia was inhibited by a cyclo-oxygenase inhibitor (indomethacin), a platelet activating factor (PAF) antagonist (BN-52021) and an inhibitor of thromboxane (econazozle), but was not affected by a lipoxygenase inhibitor (NDGA). These results suggest the involvement of eicosanoids and PAF in the immune complex hypersensitivity reaction in the rat lung and indicate the ocurrence of interactions between PAF and thromboxane