1,079 research outputs found
Dexamethasone and RU24858 induce survival and growth factor receptor bound protein 2, leukotriene B4 receptor 1 and annexin-1 expression in primary human neutrophils
Glucocorticoids are widely used anti-inflammatory medication in diseases like asthma and chronic obstructive pulmonary disease. Glucocorticoids can either activate (transactivation) or inhibit (transrepression) transcription. RU24858 was introduced as a dissociated glucocorticoid and it has been reported to transrepress but not to transactivate. The aim of this study was to compare the effects of RU24858 and dexamethasone in human neutrophils. RU24858 delayed spontaneous neutrophil apoptosis and further enhanced GM-CSF- induced neutrophil survival to a similar extent as dexamethasone. Like dexamethasone RU24858 also reduced CXCL8 and MIP-1α. Unexpectedly however, RU24858 increased the expression of the glucocorticoid-inducible genes BLT-1, Annexin-1 and Grb-2 in neutrophils to a similar level as seen with dexamethasone. We have shown here that dexamethasone and RU24858 both increase Grb-2, BLT1 and Annexin-1 expression and inhibit CXCL8 and MIP-1α production. This suggests that RU24858 was not able to dissociate between transactivation and transrepression in human neutrophils but enhanced neutrophil survival. © the author(s), publisher and licensee Libertas Academica Ltd
Translational analysis of moderate to severe asthma GWAS signals into candidate causal genes and their functional, tissue-dependent and disease-related associations
Asthma affects more than 300 million people globally and is both under diagnosed and under treated. The most recent and largest genome-wide association study investigating moderate to severe asthma to date was carried out in 2019 and identified 25 independent signals. However, as new and in-depth downstream databases become available, the translational analysis of these signals into target genes and pathways is timely. In this study, unique (U-BIOPRED) and publicly available datasets (HaploReg, Open Target Genetics and GTEx) were investigated for the 25 GWAS signals to identify 37 candidate causal genes. Additional traits associated with these signals were identified through PheWAS using the UK Biobank resource, with asthma and eosinophilic traits amongst the strongest associated. Gene expression omnibus dataset examination identified 13 candidate genes with altered expression profiles in the airways and blood of asthmatic subjects, including MUC5AC and STAT6. Gene expression analysis through publicly available datasets highlighted lung tissue cell specific expression, with both MUC5AC and SLC22A4 genes showing enriched expression in ciliated cells. Gene enrichment pathway and interaction analysis highlighted the dominance of the HLA-DQA1/A2/B1/B2 gene cluster across many immunological diseases including asthma, type I diabetes, and rheumatoid arthritis. Interaction and prediction analyses found IL33 and IL18R1 to be key co-localization partners for other genes, predicted that CD274 forms co-expression relationships with 13 other genes, including the HLA-DQA1/A2/B1/B2 gene cluster and that MUC5AC and IL37 are co-expressed. Drug interaction analysis revealed that 11 of the candidate genes have an interaction with available therapeutics. This study provides significant insight into these GWAS signals in the context of cell expression, function, and disease relationship with the view of informing future research and drug development efforts for moderate-severe asthma
Relative corticosteroid insensitivity of alveolar macrophages in severe asthma compared with non-severe asthma
On testing global optimization algorithms for space trajectory design
In this paper we discuss the procedures to test a global search algorithm applied to a space trajectory design problem. Then, we present some performance indexes that can
be used to evaluate the effectiveness of global optimization algorithms. The performance
indexes are then compared highlighting the actual significance of each one of them. A number of global optimization algorithms are tested on four typical space trajectory design problems. From the results of the proposed testing procedure we infer for each pair
algorithm-problem the relation between the heuristics implemented in the solution algorithm and the main characteristics of the problem under investigation. From this analysis we derive a novel interpretation of some evolutionary heuristics, based on dynamical system
theory and we significantly improve the performance of one of the tested algorithms
Efficient Algorithms for Universal Quantum Simulation
A universal quantum simulator would enable efficient simulation of quantum
dynamics by implementing quantum-simulation algorithms on a quantum computer.
Specifically the quantum simulator would efficiently generate qubit-string
states that closely approximate physical states obtained from a broad class of
dynamical evolutions. I provide an overview of theoretical research into
universal quantum simulators and the strategies for minimizing computational
space and time costs. Applications to simulating many-body quantum simulation
and solving linear equations are discussed
Dexamethasone inhibits ozone-induced gene expression of macrophage inflammatory protein-2 in rat lung
AbstractTo address the potential role of the chemokine macrophage inflammatory protein-2 (MIP-2) in airway inflammation, we examined whether MIP-2 may play a role in ozone-induced neutrophilic inflammation of airways and its modulation by dexamethasone in rat lung. Following ozone exposure, MIP-2 mRNA expression in the lung peaked at 2 h after exposure and slowly declined thereafter. Dexamethasone suppressed ozone-induced MIP-2 mRNA expression and neutrophil accumulation in the lung. We suggest that the MIP-2 mRNA induction may switch on the neutrophilic influx observed in this model of lung inflammation. Furthermore, the MIP-2 expression is regulated by dexamethasone which may represent one of the mechanisms by which glucocorticoids exert their potent anti-inflammatory properties
Effects of cigarette smoke extract on human airway smooth muscle cells in COPD
We hypothesised that the response to cigarette smoke in airway smooth muscle (ASM) cells from smokers with chronic obstructive pulmonary disease (COPD) would be intrinsically different from smokers without COPD, producing greater pro-inflammatory mediators and factors relating to airway remodelling. ASM cells were obtained from smokers with or without COPD, and then stimulated with cigarette smoke extract (CSE) or transforming growth factor-β1. The production of chemokines and matrix metalloproteinases (MMPs) were measured by ELISA, and the deposition of collagens by extracellular matrix ELISA. The effects of CSE on cell attachment and wound healing were measured by toluidine blue attachment and cell tracker green wound healing assays. CSE increased the release of CXCL8 and CXCL1 from human ASM cells, and cells from smokers with COPD produced more CSE-induced CXCL1. The production of MMP-1, -3 and -10, and the deposition of collagen VIII alpha 1 (COL8A1) were increased by CSE, especially in the COPD group which had higher production of MMP-1 and deposition of COL8A1. CSE decreased ASM cell attachment and wound healing in the COPD group only. ASM cells from smokers with COPD were more sensitive to CSE stimulation, which may explain, in part, why some smokers develop COPD. Copyright ©ERS 2014
Phospho-p38 MAPK expression in COPD patients and asthmatics and in challenged bronchial epithelium
Background: The role of mitogen-activated protein kinases (MAPK) in regulating the inflammatory response in the airways of patients with chronic obstructive pulmonary disease (COPD) and asthmatic patients is unclear. Objectives: To investigate the expression of activated MAPK in lungs of COPD patients and in bronchial biopsies of asthmatic patients and to study MAPK expression in bronchial epithelial cells in response to oxidative and inflammatory stimuli. Methods: Immunohistochemical expression of phospho (p)-p38 MAPK, p-JNK1 and p-ERK1/2 was measured in bronchial mucosa in patients with mild/moderate (n = 17), severe/very severe (n = 16) stable COPD, control smokers (n = 16), control non-smokers (n = 9), in mild asthma (n = 9) and in peripheral airways from COPD patients (n = 15) and control smokers (n = 15). Interleukin (IL)-8 and MAPK mRNA was measured in stimulated 16HBE cells. Results: No significant differences in p-p38 MAPK, p-JNK or p-ERK1/2 expression were seen in bronchial biopsies and peripheral airways between COPD and control subjects. Asthmatics showed increased submucosal p-p38 MAPK expression compared to COPD patients (p 2O2), cytomix (tumour necrosis factor-\u3b1 + IL-1\u3b2 + interferon-\u3b3) and lipopolysaccharide (LPS) upregulated IL-8 mRNA at 1 or 2 h. p38 MAPK\u3b1 mRNA was significantly increased after H2O2 and LPS treatment. JNK1 and ERK1 mRNA were unchanged after H2O2, cytomix or LPS treatments. Conclusion: p-p38 MAPK expression is similar in stable COPD and control subjects but increased in the bronchi of mild asthmatics compared to stable COPD patients. p38 MAPK mRNA is increased after bronchial epithelial challenges in vitro. These data together suggest a potential role for this MAPK in Th2 inflammation and possibly during COPD exacerbations
The influence of waves on morphodynamic impacts of energy extraction at a tidal stream turbine site in the Pentland Firth
Extraction of energy from tidal streams has the potential to impact on the morphodynamics of areas such as sub-tidal sandbanks via alteration of hydrodynamics. Marine sediment transport is forced by both wave and tidal currents. Past work on tidal stream turbine impacts has largely ignored the contribution of waves. Here, a fully coupled hydrodynamic, spectral wave and sediment transport model is used to assess the importance of including waves in simulations of turbine impact on seabed morphodynamics. Assessment of this is important due to the additional expense of including waves in simulations. Focus is given to a sandbank in the Inner Sound of the Pentland Firth. It is found that inclusion of wave action alters hydrodynamics, although extent of alteration is dependant of wave direction. Magnitude of sediment transport is increased when waves are included in the simulations and this has implications for morphological and volumetric changes. Volumetric changes are substantially increased when wave action is included: the impact of including waves is greater than the impact of including tidal stream turbines. Therefore it is recommended that at tidal turbine array sites exposed to large swell or wind-seas, waves should be considered for inclusion in simulations of physical impact
A transcriptome-driven analysis of epithelial brushings and bronchial biopsies to define asthma phenotypes in U-BIOPRED
RATIONALE AND OBJECTIVES: Asthma is a heterogeneous disease driven by diverse immunologic and inflammatory mechanisms. We used transcriptomic profiling of airway tissues to help define asthma phenotypes. METHODS: The transcriptome from bronchial biopsies and epithelial brushings of 107 moderate-to-severe asthmatics were annotated by gene-set variation analysis (GSVA) using 42 gene-signatures relevant to asthma, inflammation and immune function. Topological data analysis (TDA) of clinical and histological data was used to derive clusters and the nearest shrunken centroid algorithm used for signature refinement. RESULTS: 9 GSVA signatures expressed in bronchial biopsies and airway epithelial brushings distinguished two distinct asthma subtypes associated with high expression of T-helper type 2 (Th-2) cytokines and lack of corticosteroid response (Group 1 and Group 3). Group 1 had the highest submucosal eosinophils, high exhaled nitric oxide (FeNO) levels, exacerbation rates and oral corticosteroid (OCS) use whilst Group 3 patients showed the highest levels of sputum eosinophils and had a high BMI. In contrast, Group 2 and Group 4 patients had an 86% and 64% probability of having non-eosinophilic inflammation. Using machine-learning tools, we describe an inference scheme using the currently-available inflammatory biomarkers sputum eosinophilia and exhaled nitric oxide levels along with OCS use that could predict the subtypes of gene expression within bronchial biopsies and epithelial cells with good sensitivity and specificity. CONCLUSION: This analysis demonstrates the usefulness of a transcriptomic-driven approach to phenotyping that segments patients who may benefit the most from specific agents that target Th2-mediated inflammation and/or corticosteroid insensitivity
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