| 1. |
- Perotin-Collard, Jeanne-Marie, et al.
(författare)
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Subtypes of eosinophilic asthma with discrete gene pathway phenotypes
- 2019
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Ingår i: European Respiratory Journal. - : European Respiratory Society Journals. - 0903-1936 .- 1399-3003. ; 54
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Blood eosinophil counts ≥0.3x109/L are used to define Type-2, eosinophilic asthma. However, differential responses to T2 biologics of patients with eosinophilic asthma suggests that this may be a heterogeneous phenotype with subsets driven by different molecular mechanisms.Methods: Blood transcriptomic data, acquired from 99 severe asthmatics from the U-BIOPRED study (62% female, mean age 54 yr, 41% on oral steroids), were clustered by topological data analysis and cluster boundaries defined by the MORSE method. Gene pathway signatures were identified by Ingenuity Pathway Analysis.Results: Analysis revealed 3 clusters with different modulated gene pathways, i.e. molecular phenotypes. Subtype 1 had high IFN-γ, low IL5, low IL13 and low IL17 gene expression, with reduced glucocorticoid-induced gene expression. Subtype 2 had low IFNγ, high IL5, high IL13 and low IL17 gene expression. Subtype 3 had low IFNγ, high IL5, high IL13 and high IL17 gene expression. Pathway analysis suggested a strong steroid response in Subtypes 2 and 3. Clinically, the three clusters were not different in respect of age, gender, prevalence of atopy, blood or sputum eosinophil counts. Subtype 3 was characterized by high neutrophil counts in blood and bronchial epithelium, frequent sinus disease and asthma exacerbations, OCS treatment, low allergic sensitisation and low exhaled NO. Subtype 1 was characterized by high exhaled NO and more frequent IgE therapy.Conclusion: This study suggests that eosinophilic severe asthma (≥0.3x109/L) can be stratified further into 3 subtypes with distinct gene expression profiles that could be developed as molecular diagnostic biomarkers to guide treatment and thereby improve patient outcomes.
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| 2. |
- Schofield, James P. R., et al.
(författare)
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Topological data analysis (TDA) of U-BIOPRED paediatric peripheral blood gene expression identified asthma phenotypes characterised by alternative splicing of glucocorticoid receptor (GR) mRNA
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Molecular stratification of childhood asthma could enable targeted therapy.Aims: Unbiased analysis of gene expression in paediatric severe (SA) and moderate/mild asthma (MA) blood samples to identify sub-phenotypes.Methods: Transcriptomic profiling by microarray analysis of blood from the U-BIOPRED paediatric cohort (Fleming ERJ 2015), pre- and school-age children, (SApre, n=62; MApre, n=42; SAsc, n=75 and MAsc, n=37). Topological data analysis (TDA) was used for unbiased clustering.Results: Sub-phenotypes, P1, P2, P3 and P4 were identified and are highlighted in the TDA network in the figure and a heatmap of selected variables. P1 (38% of the cohort, median 11 yrs) was characterised by low expression of glucocorticoid receptor (GR) mRNA splice variant with a long 3’ UTR (q = 2.43E-17), but no significant difference in the expression of glucocorticoid receptor (GR) mRNA splice variant with a short 3’ UTR. In P1, COX2 expression was up (q = 1.89E-06) and IFN-γ was down (q = 5.61E-06), characteristics of a decreased steroid response.Conclusion: Unbiased analysis of U-BIOPRED paediatric peripheral blood gene expression identified a sub-phenotype, P1, with an inhibited steroid response. P1 is associated with low expression of a splice variant of GR with a long 3’ UTR.
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| 3. |
- Ward, Helen, et al.
(författare)
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Using observations to improve modelled energy, water and carbon exchanges for urban areas
- 2015
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Ingår i: ICUC9 – 9 th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. 20-24 July 2015, Toulouse, France.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Models are an essential tool for studying how our surroundings influence us and how we, intentionally or inadvertently, influence our surroundings. The Surface Urban Energy and Water balance Scheme (SUEWS) uses a basic meteorological forcing dataset and information about the surface cover to model components of the energy and water balance. The model was initially developed based on studies in North America and is now being run for multiple locations around the world. Here, we evaluate the model at two locations in the UK. A network of micrometeorological observations exists across London, enabling comparisons between the city centre and suburbs. The central London study site is one of the most highly urbanised and densely populated to date. 120 km to the west is the typical suburban town of Swindon. At both of these locations, extensive observational datasets spanning several years have been collected, and work has been undertaken to classify the surface characteristics. However, as detailed land cover and socio-economic information may not always be available, we consider the impact on model performance of using only easily accessible data to provide the required inputs. SUEWS is evaluated against observations of energy and water balance components (including turbulent heat fluxes from eddy covariance and scintillometry techniques). SUEWS estimates evaporation using an adapted Penman-Monteith formulation with a variable surface conductance. Analysis of observed surface conductances suggests adjustments to improve model performance. CO2 fluxes, closely linked to the surface conductance, are also examined. The central London and suburban Swindon sites behave differently, in terms of both the magnitude and temporal variability of CO2 exchanges. These differences are almost entirely a result of land use and land cover, and associated patterns of human behaviour. Simple models based on anthropogenic emissions inventories provide an indication of the magnitude of the CO2 release, however, at the suburban site vegetation plays an important role in CO2 uptake and must be incorporated too. With improved modelling capability, the exposure of the population to risks such as thermal stress or flooding can be better estimated. Having validated the model, the impact of policy decisions and future climate scenarios on the wellbeing of the citizens can be assessed.
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| 4. |
- Wilson, Susan Jane, et al.
(författare)
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Periostin expression in the U-BIOPRED severe asthma bronchoscopy cohort
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Periostin (POSTN) is secreted basolaterally by bronchial epithelial cells in asthma and is expressed in the extracellular matrix where it is thought to play a role in fibrosis and is associated with airway eosinophilia.In this study we have assessed the protein expression of POSTN in bronchial biopsies by immunohistochemistry, in serum by the Elecsys Periostin Immunoassay and measured gene expression by Affymetrix arrays in bronchial biopsies, bronchial brushings and in sputum in the U-BIOPRED severe asthma study in the bronchoscopy sub-cohort, which included 4 groups; severe non-smoker asthmatics (SAns), current / ex-smoker severe asthmatics (SAs), mild-moderate asthmatics (MMA) and non-asthmatic healthy controls (HC).Subepithelial protein expression in the bronchial biopsies was higher (p=0.02) in SAns, 9.2% (IQR 5.8-12.6)(n=44) compared to SAs 6.2% (3-9.2)(n=16), and in MMA 11% (7.5-12.6)(n=32) compared to SAs (p=0.002) or HC 7.1% (5.5-10.3)(p=0.01)(n=39). There was no difference between SAns and MMA. Gene expression was higher in biopsies from SAns (n=30), -0.044 (IQR -0.425-0.508), compared to both the SAs (n=9), -0.274 (-0.590-0.200), (p=0.02) and HC (n=21), -0.377 (-0.583-0.125), (p=0.008), but similar in MMA. There was no difference between the groups in POSTN serum levels or in gene expression in bronchial brushings or sputum.In asthmatics, the biopsy protein expression correlated with the biopsy gene expression, and both correlated with eosinophils numbers in the biopsies and blood, exhaled NO, and thickness of the lamina reticularis.These results highlight the potential relevance of tissue POSTN to asthma pathophysiology however, this does not appear to be reflected by serum POSTN measures.
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