Project description:Asthma is a complex syndrome associated with episodic decompensations provoked by aeroaller-gen exposures. The underlying pathophysiological states driving exacerbations are latent in the resting state and do not adequately inform biomarker-driven therapy. A better understanding of the pathophysiological pathways driving allergic exacerbations is needed. We hypothesized that disease-associated pathways could be identified in humans by unbiased metabolomics of bron-choalveolar fluid (BALF) during the peak inflammatory response provoked by a bronchial aller-gen challenge. We analyzed BALF metabolites in samples from 12 volunteers who underwent segmental bronchial antigen provocation (SBP-Ag). Metabolites were quantified using liquid chromatography-tandem mass spectrometry (LC–MS/MS) followed by pathway analysis and cor-relation with airway inflammation. SBP-Ag induced statistically significant changes in 549 fea-tures that mapped to 72 uniquely identified metabolites. From these features, two distinct induci-ble metabolic phenotypes were identified by the principal component analysis, partitioning around medoids (PAM) and k-means clustering. Ten index metabolites were identified that in-formed the presence of asthma-relevant pathways, including unsaturated fatty acid produc-tion/metabolism, mitochondrial beta oxidation of unsaturated fatty acid, and bile acid metabolism. Pathways were validated using proteomics in eosinophils. A segmental bronchial allergen chal-lenge induces distinct metabolic responses in humans, providing insight into pathogenic and pro-tective endotypes in allergic asthma.
Project description:To better understand proteostasis in health and disease, determination of protein half-lives is essential. We improved the precision and accuracy of peptide-ion intensity based quantification in order to enable accurate determination of protein turnover in non-dividing cells using dynamic-SILAC. This enabled precise and accurate protein half-life determination ranging from 10 to more than 1000 hours. We achieve good proteomic coverage ranging from four to six thousand proteins in several types of non-dividing cells, corresponding to a total of 9699 unique proteins over the entire dataset. Good agreement was observed in half-lives between B-cells, natural killer cells and monocytes, while hepatocytes and mouse embryonic neurons showed substantial differences. Our comprehensive dataset enabled extension and statistical validation of the previous observation that subunits of protein complexes tend to have coherent turnover. Furthermore, we observed complex architecture dependent turnover within complexes of the proteasome and the nuclear pore complex. Our method is broadly applicable and might be used to investigate protein turnover in various cell types.
Project description:Bronchial Epithelial Cells were isolated processed as described (Chu et al., 2002 and Zhao et al., 2011). The objective of the study was to identify differentially expressed genes between normal control (NC), mild-moderate asmathic (notSA) and severe asthmatic (SA) patients. For demographics data, contact Dr. Sally Wenzel (wenzelse@upmc.edu) Bronchoscopy with endobronchial epithelial brushing was performed as previously described (Chu et al., 2002; Zhao et al., 2011). Bronchial alveolar lavage fluids were spun down on 4000 g for 10 minutes. 0.5- 1X10^6 cells were stored in Trizol for RNA extraction. RNA in Trizol solution was extracted using the QIACube system (Qiagen, Valencia, CA). RNA quality was determined using the Agilent Bioanalyzer 2100 (Agilent Technologies, Santa Clara, CA), and only samples with an RIN higher than 7 used for microarray experiments.
Project description:Bronchial Epithelial Cells were isolated processed as described (Chu et al., 2002 and Zhao et al., 2011). The objective of the study was to identify differentially expressed genes between normal control (NC), mild-moderate asmathic (notSA) and severe asthmatic (SA) patients. For demographics data, contact Dr. Sally Wenzel (wenzelse@upmc.edu)
Project description:ObjectivesWe hypothesised that severe asthmatics taking a statin drug, in addition to inhaled corticosteroids/long-acting ?-agonist inhaler therapy, would have better asthma symptom control and improved lung function compared to their controls.Study designA retrospective, cross-sectional study of 165 patients with severe asthma seen from 2001-2008. Hierarchical linear and logistic regression models were used for modelling fitting.SettingUniversity of California, Davis Medical Center (Sacramento, California, USA). Academic, single-centre, severe asthma subspecialty clinic.Participants612 screened, 223 eligible and 165 adult patients were included in the final study (N=165; 31 statin users and 134 non-users).Primary and secondary outcome measuresThe primary endpoint was asthma control as measured by the Asthma Control Test (ACT). The secondary endpoints included lung function, symptoms and the need for corticosteroid burst and peripheral eosinophil count.ResultsAt baseline, statin users compared to non-users were older, had lower lung function (FEV1% predicted, FEV1, forced vital capacity and FEF25-75%) and had a higher prevalence of comorbid conditions. Statin use was associated with more aspirin and ipratropium inhaler use than in non-users. Patients in both groups were obese (body mass index ? 30). Statin users had better asthma symptom control compared to non-users (higher adjusted mean ACT score by 2.2±0.94 points, p<0.02). Median statin use was for 1 year. There were no statistically significant differences in lung function, corticosteroid or rescue bronchodilator use or peripheral eosinophilia between the two groups.ConclusionsIn our severe asthma referral population, statin users already taking inhaled controller therapy achieved better asthma control compared to non-users. The implications of this study is that patients with severe asthma could potentially benefit from added statin treatment. Because our study population was on average obese, the obese severe asthmatic may be a viable asthma subphenotype for further studies. Prospective randomised clinical trials evaluating the safety and efficacy of statins in severe asthma are warranted.
Project description:Viral-induced severe asthma exacerbations in children are characterized by IRF7hi and IRF7lo molecular phenotypes. We have developed an experimental animal model that mirrors these response patterns in asthma-resistant PVG and asthma-susceptible BN rats respectively. We aimed to i) characterize the immunological and molecular hallmarks of PVG and BN responses to virus/allergen exposure, and (ii) evaluate the utility of innate immune training with the bacterial lysate OM85 to attenuate ensuing inflammation. Animals were sensitized to OVA/alum, inoculated with murine-adapted Rhinovirus model (vMC0), and challenged with OVA 24h later. RNA-seq was performed on lung and bone marrow at several time points post virus/allergen exposure.