On November 18, 2011, the 16th annual Alcohol and Immunology Research Interest Group (AIRIG) meeting was held at Loyola University Medical Center in Maywood, Illinois. The focus of this year's meeting was alcohol's effect on epigenetic changes and possible outcomes induced by these changes. Two sessions, which consisted of talks from invited speakers as well as presentations of selected abstracts, were held in addition to a poster session. Participants presented information on alcohol-induced alterations in histone modifications and gene expression along with immunologic responses to alcohol. Speakers shared new research specifically on histone deacetylase enzyme expression and modifications due to alcohol and the downstream effect of these modifications may have on gene expression and tissue damage. Additional studies suggested that alcohol exacerbates inflammation when combined with other insults such as infection, trauma, inhalation injury, and disease.

Background: Diesel exhaust particle (DEP) exposure enhances allergic inflammation and has been linked to the incidence of asthma. Oxidative stress on the thiol molecules cysteine (Cys) and glutathione (GSH) can promote inflammatory host responses. The effect of DEP on the thiol oxidation/reduction (redox) state in the asthmatic lung is unknown. Objective: To determine if DEP exposure alters the Cys or GSH redox state in the asthmatic airway. Methods: Bronchoalveolar lavage fluid was obtained from a house dust mite (HDM) induced murine asthma model exposed to DEP. GSH, glutathione disulfide (GSSG), Cys, cystine (CySS), and s-glutathionylated cysteine (CySSG) were determined by high pressure liquid chromatography. Results: DEP co-administered with HDM, but not DEP or HDM alone, decreased total Cys, increased CySS, and increased CySSG without significantly altering GSH or GSSG. Conclusions: DEP exposure promotes oxidation and S-glutathionylation of cysteine amino acids in the asthmatic airway, suggesting a novel mechanism by which DEP may enhance allergic inflammatory responses. © 2013 Lee et al.

Airway cellular dysfunction is a differentiating feature of severe asthma in children that may be related to an imbalance of the antioxidant, glutathione (GSH). We hypothesized that oxidation of GSH to glutathione disulfide (GSSG) in the epithelial lining fluid (ELF) of children with severe asthma would contribute to altered airway macrophage (AM) GSH homeostasis and AM cellular dysfunction. Bronchoalveolar lavage (BAL) was performed in 64 asthmatic children (severe asthma, n = 43). GSH, GSSG, markers of lipid peroxidation and DNA oxidation, and IL-8 were quantified in the BAL supernatant. GSH, GSSG, activities of histone deacetylase (HDAC) and histone acetyltransferase, apoptosis, and phagocytosis were assessed in isolated AMs. Children with severe asthma had increased GSSG, lipid peroxidation, byproducts of DNA oxidation, and inflammation in the ELF. This imbalance of GSH homeostasis was also noted intracellularly within the AMs and was associated with decreased HDAC activities, increased apoptosis, and impaired phagocytosis. In vitro GSH supplementation inhibited apoptosis and rescued phagocytosis in children with severe asthma. Severe asthma in children is characterized by altered airway and intracellular AM GSH homeostasis that translates to impaired AM function. Interventions to restore airway GSH homeostasis may be warranted in children with severe asthma.

Background Transforming growth factor beta-1 (TGFβ1) is thought to play a role in airway remodeling in asthma. TGFβ1 expression may be mediated by an excessive burden of reactive oxygen species and oxidant stress. Objective Given the profound airway oxidant stress we have previously observed in children with severe asthma, we sought to: 1) quantify TGFβ1 protein and mRNA gene expression in the airways of children with mild-to-moderate and severe atopic asthma; and to 2) determine the relationship of airway TGFβ1 concentrations to oxidant burden (i.e., lipid peroxidation), Th2-mediated eosinophilic inflammation, and airflow limitation. Methods Bronchoalveolar lavage fluid was collected from 68 atopic children with asthma (severe asthma, n = 28) and 12 atopic adult controls. Airway TGFβ1 expression and activation were assessed in relation to airway IL-13, 8-isoprostane, and malondialdehyde concentrations. The relationship of airway TGFβ1 expression to airflow limitation in children with asthma was also assessed. Results Children with severe asthma had higher total airway concentrations of TGFβ1 that were associated with increased protein and mRNA expression of TGFβ1 in airway macrophages and an increase in the lipid peroxidation biomarkers 8-isoprostanes and malondialdehyde. TGFβ1 activation was also greater in children with severe asthma and was associated with higher airway 8-isoprostane, malondialdehyde and IL-13 concentrations. Total airway TGFβ1 concentrations were further associated with airflow limitation. Conclusions Children with severe asthma have increased airway TGFβ1 expression and activation associated with an increased airway oxidant burden. Oxidant stress may mediate the effects of TGFβ1 and promote airway remodeling in children with severe asthma.

Summary Children with moderate-to-severe asthma have decreased expression of acetaminophen metabolizing genes and glutathione that may account for the previously-reported risk of acetaminophen in this vulnerable population.

Rationale Airway thiol redox disturbances, including depletion of the antioxidant, glutathione (GSH), are differentiating features of severe asthma in children. Objectives Given the role of the transcription factor, Nrf2, in maintaining GSH homeostasis and antioxidant defense, we quantified expression and activity of Nrf2 and its downstream targets in the airways and systemic circulation of asthmatic children. We hypothesized that Nrf2 activation and function would be impaired in severe asthma, resulting in depletion of thiol pools and insufficient GSH synthesis and conjugation. Methods Peripheral blood mononuclear cells (PBMCs) and airway lavage cells were collected from children 6–17 years with severe (n=51) and mild-to-moderate asthma (n=38). The thiols GSH and cysteine (CyS) were quantified and expression and activity of Nrf2 and its downstream targets were assessed. Results Children with severe asthma had greater oxidation and lower concentrations of GSH and Cys in the plasma and airway lavage. Although Nrf2 mRNA and protein increased in severe asthma as a function of increased thiol oxidation, the Nrf2 expressed was highly dysfunctional. Nrf2 activation and downstream targets of Nrf2 binding, including GSH-dependent enzymes, were not different between groups. The duration of asthma was a key factor associated with Nrf2 dysfunction in severe asthma. Conclusions Children with severe asthma have a global disruption of thiol redox signaling and control in both the airways and systemic circulation that is associated with post-translational modification of Nrf2. We conclude that the Nrf2 pathway is disrupted in severe asthma as a function of chronic oxidative stress, which ultimately inhibits GSH synthesis and antioxidant defense.

Background Children with severe allergic asthma have persistent airway inflammation and oxidant stress. Objectives We hypothesized that children with severe allergic asthma would have increased concentrations of the NO oxidation products nitrite, nitrate, and nitrotyrosine in the proximal and distal airway epithelial lining fluid (ELF). We further hypothesized that NO oxidation products would be associated with higher exhaled nitric oxide (FENO), greater allergic sensitization, and lower pulmonary function. Methods Bronchoalveolar lavage (BAL) was obtained from 15 children with mild-to-moderate asthma, 30 children with severe allergic asthma, 5 non-asthmatic children and 20 non-smoking adults. The BAL was divided into proximal and distal portions and nitrite, nitrate, and nitrotyrosine were quantified. Results Children with mild-to-moderate and severe allergic asthma had increased concentrations of nitrite (adult control: 15 ± 3; pediatric control: 23 ± 4; mild-to-moderate asthma: 56 ± 26; severe asthma: 74 ± 18 µM), nitrate (37 ± 13 vs. 145 ± 38 vs. 711 ± 155 vs. 870 ± 168 µM) and nitrotyrosine (2 ± 1 vs. 3 ± 1 vs. 9 ± 3 vs. 10 ± 4 µM) in the proximal ELF. Similar results were seen in the distal ELF although the concentrations were significantly lower (p < 0.05 for each). Although univariate analyses revealed no associations between NO oxidation products and clinical features, multivariate analyses revealed FENO to be a significant predictor of NO oxidation in asthmatic children. Conclusions NO oxidation products are increased in the ELF of asthmatic children. The relationship between FENO and airway nitrosative stress is complicated and requires further study.

Background Severe asthma is characterized by persistent airway inflammation and increased formation of reactive oxygen species. Objectives Glutathione (GSH) is an important antioxidant in the epithelial lining fluid (ELF). We hypothesized that airway GSH homeostasis was altered in children with severe asthma and was characterized by decreased GSH and increased glutathione disulfide (GSSG) concentrations. Methods Bronchoalveolar lavage was obtained from 65 children with severe asthma, including 35 children with baseline airway obstruction evidenced by FEV1 <80%. Control data were obtained from 6 children with psychogenic (habit) cough or vocal cord dysfunction undergoing diagnostic bronchoscopy and 35 healthy adult controls. GSH, GSSG, and other determinants of airway oxidative stress including glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), malondialdehyde, 8-isoprostane, and H2O2 were measured in the ELF. The ELF redox potential was calculated from GSH and GSSG by using the Nernst equation. Results: Compared with controls, subjects with severe asthma had lower airway GSH with increased GSSG despite no differences in GST, GR, and GPx activities between groups. This was accompanied by increased malondialdehyde, 8-isoprostane, and H2O2 concentrations in the ELF. GSH oxidation was most apparent in subjects with severe asthma with airway obstruction and was supported by an upward shift in the ELF GSH redox potential. Conclusion Children with severe asthma have increased biomarkers of oxidant stress in the ELF that are associated with increased formation of GSSG and a shift in the GSH redox potential toward the more oxidized state.

Background Lower respiratory tract infection is a differentiating feature of children with poorly controlled asthma. Objective: Given the role of alveolar macrophages (AMs) in innate immunity, we hypothesized that AM phagocytosis might be impaired in poorly controlled asthma. Methods Bronchoalveolar lavage fluid AMs were isolated from 28 asthmatic children (moderate asthma, n = 12; severe asthma, n = 16), 10 nonasthmatic children with chronic cough treated with inhaled corticosteroids, and 10 healthy adult control subjects. AMs were stimulated with LPS and exposed to fluorescein isothiocyanate–conjugated Staphylococcus aureus for 2 hours. Phagocytosis was quantified by using a phagocytic index (PI) calculated from the percentage of phagocytic cells multiplied by the relative fluorescence (RFU) units of S aureus per cell. Apoptosis was determined from the percentage of cells positive for poly (adenosine diphosphate–ribose) polymerase. Results Phagocytosis as measured by using the unstimulated PI was decreased in subjects with poorly controlled asthma (healthy control subjects, 9330 ± 3992 RFU; chronic cough, 9042 ± 5976 RFU; moderate asthma, 4361 ± 2536 RFU; severe asthma, 3153 ± 1886 RFU; P < .001) and remained unchanged with LPS stimulation. Children with severe asthma also had increased AM apoptosis, both the unstimulated and LPS-simulated states (P < .001), which correlated with the PI. Conclusions AM function is compromised in children with poorly controlled asthma and is characterized by decreased phagocytosis and increased apoptosis.