Intratracheal instillation of lipopolysaccharide in mice induces apoptosis in bronchial epithelial cells: no role for tumor necrosis factoralpha and infiltrating neutrophils

This study investigated apoptosis in lungs after local exposure to lipopolysaccharide (LPS). Mice were instilled intratracheally with 5 �g LPS, which corresponds to the amount acquired by smoking approximately 25 cigarettes, and killed at different time points after exposure. Our data demonstrate that local LPS exposure resulted in apoptosis in lungs from 2 h and peaked at 24 h, as detected by ligation-mediated polymerase chain reaction. Morphologic examination and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end label staining demonstrated apoptosis in bronchial epithelial cells early after intratracheal (IT) LPS challenge, whereas infiltrating neutrophils displayed positive staining at 24 and 72 h after exposure. Apoptosis in lungs clearly preceded pulmonary neutrophil infiltration, confirming that neutrophils did not contribute to pulmonary apoptosis at early time points. Further

NF-kappa B Activation is Required for the Transition of Pulmonary Inflammation to Muscle Atrophy

Rationale Disease exacerbations and muscle wasting are negative prognostic factors of COPD. Transient systemic inflammation and malnutrition have been implicated in skeletal muscle wasting following acute exacerbations of COPD. However, the interaction between systemic inflammation and malnutrition in their contribution to muscle atrophy, as well as the molecular basis underlying the transition of systemic inflammation to muscle atrophy remain unresolved.Methods Pulmonary inflammation was induced in mice by intra-tracheal (IT) lipopolysaccharide (LPS) instillation to model acute disease exacerbation. Systemic inflammation, nutritional intake, body and muscle weights were determined. Muscle inflammatory and atrophy signalling were examined, and the effect of muscle specific inactivation of Nuclear Factor kappa B (NF-kB) on muscle atrophy was assessed in genetically modified mice. Results IT-LPS instillation was followed by markedly elevated circulating cytokine levels and NF-kB activation in extra-pulmonary tissues, including skeletal muscle. IT-LPS administration increased the expression of muscle E3 Ub-ligases which govern muscle proteolysis, in particular MuRF1, and caused rapid loss of muscle mass. Reduced food intake only partially accounted for the observed muscle atrophy and did not activate NF-kB in muscle. Rather, plasma transfer experiments revealed the presence of NF-kB- and atrophy-signalling properties in the circulation of IT-LPS treated mice. Genetic inhibition of muscle NF-kB activity suppressed IT-LPS-induced MuRF1 expression and resulted in significant sparing of muscle tissue. Conclusion Systemic inflammation and malnutrition contribute to muscle wasting induced by acute pulmonary inflammation via distinct mechanisms, and muscle NF-kB activation is required for the transition from inflammatory to muscle atrophy signallin

Myeloperoxidase Deficiency Attenuates Lipopolysaccharide-Induced Acute Lung Inflammation and Subsequent Cytokine and Chemokine Production

Lung neutrophilia is common to a variety of lung diseases. The production of reactive oxygen and nitrogen species during neutrophil oxidative burst has been associated with protein and DNA damage. Myeloperoxidase (MPO) is an enzyme stored in the azurophilic granula of neutrophils. It is important in host defense because it generates the reactive oxidant hypochlorous acid and has been described to play a role in the activation of neutrophils during extravasation. We hypothesized that MPO contributes directly to the development of acute lung neutrophilia via stimulation of neutrophil extravasation and indirectly to the subsequent production of cytokines and chemokines in the lung. To test this hypothesis, wild-type (WT) and Mpo(-/-) mice were given a single LPS instillation, after which the development of neutrophil-dominated lung inflammation, oxidative stress, and cytokine and chemokine levels were examined. Mpo(-/-) mice demonstrated a decreased lung neutrophilia that peaked earlier than neutrophilia in WT mice, which can be explained by decreased neutrophil chemoattractant levels in LPS-exposed Mpo(-/-) compared with WT mice. However, oxidative stress levels were not different in LPS-exposed WT and Mpo(-/-) mice. Furthermore, in vivo findings were confirmed by in vitro studies, using isolated neutrophils. These results indicate that MPO promotes the development of lung neutrophilia and indirectly influences subsequent chemokine and cytokine production by other cell types in the lung. The Journal of Immunology, 2009, 182: 7990-7996

Patterns of inflammation and the use of reversibility testing in smokers with airway complaints.

Contains fulltext : 50193.pdf (publisher's version ) (Open Access)BACKGROUND: Although both smoking and respiratory complaints are very common, tools to improve diagnostic accuracy are scarce in primary care. This study aimed to reveal what inflammatory patterns prevail in clinically established diagnosis groups, and what factors are associated with eosinophilia. METHOD: Induced sputum and blood plasma of 59 primary care patients with COPD (n = 17), asthma (n = 11), chronic bronchitis (CB, n = 14) and smokers with no respiratory complaints ('healthy smokers', n = 17) were collected, as well as lung function, smoking history and clinical work-up. Patterns of inflammatory markers per clinical diagnosis and factors associated with eosinophilia were analyzed by multiple regression analyses, the differences expressed in odds ratios (OR) with 95% confidence intervals. RESULTS: Multivariately, COPD was significantly associated with raised plasma-LBP (OR 1.2 [1.04-1.37]) and sTNF-R55 in sputum (OR 1.01 [1.001-1.01]), while HS expressed significantly lowered plasma-LBP (OR 0.8 [0.72-0.95]). Asthma was characterized by higher sputum eosinophilic counts (OR 1.3 [1.05-1.54]), while CB showed a significantly higher proportion of sputum lymphocytic counts (OR 1.5 [1.12-1.9]). Sputum eosinophilia was significantly associated with reversibility after adjusting for smoking, lung function, age, gender and allergy. CONCLUSION: Patterns of inflammatory markers in a panel of blood plasma and sputum cells and mediators were discernable in clinical diagnosis groups of respiratory disease. COPD and so-called healthy smokers showed consistent opposite associations with plasma LBP, while chronic bronchitics showed relatively predominant lymphocytic inflammation compared to other diagnosis groups. Only sputum eosinophilia remained significantly associated with reversibility across the spectrum of respiratory disease in smokers with airway complaints