Effect of acute ozone exposure on the lung metabolomes of obese and lean mice.

Pulmonary responses to the air pollutant, ozone, are increased in obesity. Both obesity and ozone cause changes in systemic metabolism. Consequently, we examined the impact of ozone on the lung metabolomes of obese and lean mice. Lean wildtype and obese db/db mice were exposed to acute ozone (2 ppm for 3 h) or air. 24 hours later, the lungs were excised, flushed with PBS to remove blood and analyzed via liquid-chromatography or gas-chromatography coupled to mass spectrometry for metabolites. Both obesity and ozone caused changes in the lung metabolome. Of 321 compounds identified, 101 were significantly impacted by obesity in air-exposed mice. These included biochemicals related to carbohydrate and lipid metabolism, which were each increased in lungs of obese versus lean mice. These metabolite changes may be of functional importance given the signaling capacity of these moieties. Ozone differentially affected the lung metabolome in obese versus lean mice. For example, almost all phosphocholine-containing lysolipids were significantly reduced in lean mice, but this effect was attenuated in obese mice. Glutathione metabolism was also differentially affected by ozone in obese and lean mice. Finally, the lung metabolome indicated a role for the microbiome in the effects of both obesity and ozone: all measured bacterial/mammalian co-metabolites were significantly affected by obesity and/or ozone. Thus, metabolic derangements in obesity appear to impact the response to ozone.

IL-33 Drives Augmented Responses to Ozone in Obese Mice.

BACKGROUND: Ozone increases IL-33 in the lungs, and obesity augments the pulmonary effects of acute ozone exposure. OBJECTIVES: We assessed the role of IL-33 in the augmented effects of ozone observed in obese mice. METHODS: Lean wildtype and obese db/db mice were pretreated with antibodies blocking the IL-33 receptor, ST2, and then exposed to ozone (2 ppm for 3 hr). Airway responsiveness was assessed, bronchoalveolar lavage (BAL) was performed, and lung cells harvested for flow cytometry 24 hr later. Effects of ozone were also assessed in obese and lean mice deficient in γδ T cells and their wildtype controls. RESULTS AND DISCUSSION: Ozone caused greater increases in BAL IL-33, neutrophils, and airway responsiveness in obese than lean mice. Anti-ST2 reduced ozone-induced airway hyperresponsiveness and inflammation in obese mice but had no effect in lean mice. Obesity also augmented ozone-induced increases in BAL CXCL1 and IL-6, and in BAL type 2 cytokines, whereas anti-ST2 treatment reduced these cytokines. In obese mice, ozone increased lung IL-13+ innate lymphoid cells type 2 (ILC2) and IL-13+ γδ T cells. Ozone increased ST2+ γδ T cells, indicating that these cells can be targets of IL-33, and γδ T cell deficiency reduced obesity-related increases in the response to ozone, including increases in type 2 cytokines. CONCLUSIONS: Our data indicate that IL-33 contributes to augmented responses to ozone in obese mice. Obesity and ozone also interacted to promote type 2 cytokine production in γδ T cells and ILC2 in the lungs, which may contribute to the observed effects of IL-33. Citation: Mathews JA, Krishnamoorthy N, Kasahara DI, Cho Y, Wurmbrand AP, Ribeiro L, Smith D, Umetsu D, Levy BD, Shore SA. 2017. IL-33 drives augmented responses to ozone in obese mice. Environ Health Perspect 125:246-253; http://dx.doi.org/10.1289/EHP272.

Innate and ozone-induced airway hyperresponsiveness in obese mice: role of TNF-α.

Innate airway hyperresponsiveness (AHR) and augmented responses to ozone, an asthma trigger, are characteristics of obese mice. Systemic inflammation, a condition of increased circulating concentrations of inflammatory moieties, occurs in obesity. We hypothesized that TNF-α, via its effects as a master effector of this systemic inflammation, regulates innate AHR and augmented responses to ozone in obese mice. Therefore, we examined pulmonary inflammation and airway responsiveness in unexposed or ozone-exposed (2 ppm for 3 h) lean wild-type and obese Cpe(fat) mice that were TNF-α sufficient or deficient. Cpe(fat) mice lack carboxypeptidase E, which regulates satiety. Compared with wild type, Cpe(fat) mice had elevated serum IL-17A, G-CSF, KC, MCP-1, IL-9, MIG, and leptin, indicating systemic inflammation. Despite reductions in most of these moieties in TNF-α-deficient vs. -sufficient Cpe(fat) mice, we observed no substantial difference in airway responsiveness in these two groups of mice. Ozone-induced increases in bronchoalveolar lavage (BAL) neutrophils and macrophages were lower, but ozone-induced AHR and increases in BAL hyaluronan, osteopontin, IL-13, and protein carbonyls, a marker of oxidative stress, were augmented in TNF-α-deficient vs. -sufficient Cpe(fat) mice. Our data indicate that TNF-α has an important role in promoting the systemic inflammation but not the innate AHR of obesity, suggesting that the systemic inflammation of obesity is not the major driver of this AHR. TNF-α is required for the augmented effects of acute ozone exposure on pulmonary inflammatory cell recruitment in obese mice, whereas TNF-α protects against ozone-induced AHR in obese mice, possibly by suppressing ozone-induced oxidative stress.

Augmented pulmonary responses to acute ozone exposure in obese mice: roles of TNFR2 and IL-13.

BACKGROUND: Acute ozone (O(3)) exposure results in greater inflammation and airway hyperresponsiveness (AHR) in obese versus lean mice. OBJECTIVES: We examined the hypothesis that these augmented responses to O(3) are the result of greater signaling through tumor necrosis factor receptor 2 (TNFR2) and/or interleukin (IL)-13. METHODS: We exposed lean wild-type (WT) and TNFR2-deficient (TNFR2(-/-)) mice, and obese Cpe(fat) and TNFR2-deficient Cpe(fat) mice (Cpe(fat)/TNFR2(-/-)), to O(3) (2 ppm for 3 hr) either with or without treatment with anti-IL-13 or left them unexposed. RESULTS: O(3)-induced increases in baseline pulmonary mechanics, airway responsiveness, and cellular inflammation were greater in Cpe(fat) than in WT mice. In lean mice, TNFR2 deficiency ablated O(3)-induced AHR without affecting pulmonary inflammation; whereas in obese mice, TNFR2 deficiency augmented O(3)-induced AHR but reduced inflammatory cell recruitment. O(3) increased pulmonary expression of IL-13 in Cpe(fat) but not WT mice. Flow cytometry analysis of lung cells indicated greater IL-13-expressing CD(4+) cells in Cpe(fat) versus WT mice after O(3) exposure. In Cpe(fat) mice, anti-IL-13 treatment attenuated O(3)-induced increases in pulmonary mechanics and inflammatory cell recruitment, but did not affect AHR. These effects of anti-IL-13 treatment were not observed in Cpe(fat)/TNFR2(-/-) mice. There was no effect of anti-IL-13 treatment in WT mice. CONCLUSIONS: Pulmonary responses to O(3) are not just greater, but qualitatively different, in obese versus lean mice. In particular, in obese mice, O(3) induces IL-13 and IL-13 synergizes with TNF via TNFR2 to exacerbate O(3)-induced changes in pulmonary mechanics and inflammatory cell recruitment but not AHR.

Cigarette smoke dissociates inflammation and lung remodeling in OVA-sensitized and challenged mice.

We evaluated the effects of cigarette smoke (CS) on lung inflammation and remodeling in a model of ovalbumin (OVA)-sensitized and OVA-challenged mice. Male BALB/c mice were divided into 4 groups: non-sensitized and air-exposed (control); non-sensitized and exposed to cigarette smoke (CS), sensitized and air-exposed (OVA) (50 µg+OVA 1% 3 times/week for 3 weeks) and sensitized and cigarette smoke exposed mice (OVA+CS). IgE levels were not affected by CS exposure. The increases in total bronchoalveolar fluid cells in the OVA group were attenuated by co-exposure to CS, as were the changes in IL-4, IL-5, and eotaxin levels as well as tissue elastance (p<0.05). In contrast, only the OVA+CS group showed a significant increase in the protein expression of IFN-γ, VEGF, GM-CSF and collagen fiber content (p<0.05). In our study, exposure to cigarette smoke in OVA-challenged mice resulted in an attenuation of pulmonary inflammation but led to an increase in pulmonary remodeling and resulted in the dissociation of airway inflammation from lung remodeling.

Cholinergic hyperresponsiveness of peripheral lung parenchyma in chronic obstructive pulmonary disease.

BACKGROUND: Up to 60% of chronic obstructive pulmonary disease (COPD) patients can present airway hyperresponsiveness. However, it is not known whether the peripheral lung tissue also shows an exaggerated response to agonists in COPD. OBJECTIVES: To investigate the in vitro mechanical behavior and the structural and inflammatory changes of peripheral lung tissue in COPD patients and compare to nonsmoking controls. METHODS: We measured resistance and elastance at baseline and after acetylcholine (ACh) challenge of lung strips obtained from 10 COPD patients and 10 control subjects. We also assessed the alveolar tissue density of neutrophils, eosinophils, macrophages, mast cells and CD8+ and CD4+ cells, as well as the content of α-smooth muscle actin-positive cells and elastic and collagen fibers. We further investigated whether changes in in vitro parenchymal mechanics correlated to structural and inflammatory parameters and to in vivo pulmonary function. RESULTS: Values of resistance after ACh treatment and the percent increase in tissue resistance (%R) were higher in the COPD group (p ≤ 0.03). There was a higher density of macrophages and CD8+ cells (p < 0.05) and a lower elastic content (p = 0.003) in the COPD group. We observed a positive correlation between %R and eosinophil and CD8+ cell density (r = 0.608, p = 0.002, and r = 0.581, p = 0.001, respectively) and a negative correlation between %R and the ratio of forced expiratory volume in 1 s to forced vital capacity (r = -0.451, p < 0.05). CONCLUSIONS: The cholinergic responsiveness of parenchymal lung strips is increased in COPD patients and seems to be related to alveolar tissue eosinophilic and CD8 lymphocytic inflammation and to the degree of airway obstruction on the pulmonary function test.

Chronic exposure to ambient levels of urban particles affects mouse lung development.

RATIONALE: Chronic exposure to air pollution has been associated with adverse effects on children's lung growth. OBJECTIVES: We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development. METHODS: The exposure occurred in two open-top chambers (filtered and nonfiltered) placed 20 m from a street with heavy traffic in São Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM(2.5) inside the filtered chamber (filtered = 2.9 +/- 3.0 microg/m(3), nonfiltered = 16.8 +/- 8.3 microg/m(3); P = 0.001). At this exposure site, vehicular sources are the major components of PM(2.5) (PM

Acrolein inhalation suppresses lipopolysaccharide-induced inflammatory cytokine production but does not affect acute airways neutrophilia.

Acrolein is a reactive unsaturated aldehyde that is produced during endogenous oxidative processes and is a major bioactive component of environmental pollutants such as cigarette smoke. Because in vitro studies demonstrate that acrolein can inhibit neutrophil apoptosis, we evaluated the effects of in vivo acrolein exposure on acute lung inflammation induced by LPS. Male C57BL/6J mice received 300 microg/kg intratracheal LPS and were exposed to acrolein (5 parts per million, 6 h/day), either before or after LPS challenge. Exposure to acrolein either before or after LPS challenge did not significantly affect the overall extent of LPS-induced lung inflammation, or the duration of the inflammatory response, as observed from recovered lung lavage leukocytes and histology. However, exposure to acrolein after LPS instillation markedly diminished the LPS-induced production of several inflammatory cytokines, specifically TNF-alpha, IL-12, and the Th1 cytokine IFN-gamma, which was associated with reduction in NF-kappaB activation. Our data demonstrate that acrolein exposure suppresses LPS-induced Th1 cytokine responses without affecting acute neutrophilia. Disruption of cytokine signaling by acrolein may represent a mechanism by which smoking contributes to chronic disease in chronic obstructive pulmonary disease and asthma.

Educational program for smoke-induced respiratory diseases in Brazilian Amazon: assessing knowledge about asthma.

Economic and cultural considerations underlie the forest clearing by burning that occurs in the Brazilian Amazon region. The prevalence of respiratory diseases markedly increases during the annual burning season. As part of a nongovernmental initiative to reduce forest fires, health professionals received updated training about respiratory diseases aggravated by smoke. The aim of the present study was to describe and evaluate this educational program. A total of 1500 health care professionals received theoretical and practical guidance. Some of the involved community health agents (CHA) and nurse technicians completed a questionnaire that assessed knowledge about asthma before and after training. Asthma was recognized as an inflammatory disease by 274 of 743 (36%) CHA and nurse technicians on the initial questionnaire compared with 542 of 684 (80%) on the final questionnaire (p < 0.0001). The concept that asthma and allergic bronchitis are the same disease was initially acknowledged by 250 of 743 (33%) CHA and nurse technicians compared with 671 of 684 (90%) after the training (p < 0.0001). The usefulness of bronchodilators was identified by 442 of 743 (60%) CHA and nurse technicians before the training vs. 497 of 684 (73%) after the training (p < 0.0001). Training significantly influenced knowledge about asthma in the group studied. The impact of this program on health care remains unknown.

Beta-2 agonista como imunomodulador da resposta inflamatória oulmonar crônica induzida em camundongos awnaibilizados com ovoalbumina / B2-agonist as immunomodulator of chronic lung inflammatory response induced in mice sensitized with ovallbumin

Agonista de receptor b2-adrenérgico pode apresentar efeito imunomodulador. Estudamos a influência do salbutamol sobre a inflamação pulmonar crônica induzida por ovoalbumina em camundongos Balb/c, nos regimes a cada 96 horas (IS) e no regime diário (DS). Houve aumento expressivo de eosinófilos e neutrófilos no lavado broncoalveolar no modelo, a qual foi reduzida após DS. A OVA aumentou a quantidade de células LMN e EPO+ na parede de vias aéreas e no parênquima pulmonar / Beta2-adrenergic receptor agonist showed a imunomodulator effects. We study the influence of intermittent (IS) and diary (DS) regimen of salbutamol on ovalbumin induced chronic lung inflammation. Expressive increasing of eosinophils and neutrophils were observed in bronchoalveolar lavage from our model...

Comparison of knowledge on asthma: doctors completing internal medicine residency and doctors completing medical school

CONTEXT: Asthma has been reported as a disease of increasing prevalence. OBJECTIVE: To assess the level of information and knowledge about asthma by means of a questionnaire among recent graduate physicians applying for medical residency at the Clinical Hospital of the University of Säo Paulo Medical School, Brazil. DESIGN: 14 multiple-choice questions for asthma diagnosis and management. SETTING: University of Säo Paulo Medical School (FMUSP). PARTICIPANTS: Recent graduate physicians applying for the medical residency program at FMUSP in 1999 (n = 448) and physicians that had completed 2 year of internal medicine residency (n = 92). MAIN MEASUREMENTS: We applied a questionnaire with 14 multiple-choice questions about the management of asthma based upon the Expert Panel Report 2 - Guidelines for the Diagnosis and Management of Asthma, NIH/NHLBI, 1997 (EPR-2). RESULTS: The medical residency program in Internal Medicine improved treatment skills (the ability to propose adequate therapy) when compared to medical education (a score of 57.2 percent versus 46.9 percent, P < 0.001) but not diagnosis knowledge (understanding of asthma symptoms related to medicine intake) (33.5 percent versus 33.3 percent, P = 0.94). Treatment skills were higher among physicians who received their Medical Degree (MD) from public-sponsored medical schools in comparison with those from private schools [49.7 (SE 1.17)] versus [41.8 (SE 1.63)], P < 0.001. CONCLUSION: Medical schools might consider reevaluating their programs regarding asthma in order to improve medical assistance, especially when considering the general results for residents, as they were supposed to have achieved performance after completing this in-service training