Tensin1 expression and function in chronic obstructive pulmonary disease

open access articleChronic obstructive pulmonary disease (COPD) constitutes a major cause of morbidity and mortality. Genome wide association studies have shown significant associations between airflow obstruction or COPD with a non-synonymous SNP in the TNS1 gene, which encodes tensin1. However, the expression, cellular distribution and function of tensin1 in human airway tissue and cells are unknown. We therefore examined these characteristics in tissue and cells from controls and people with COPD or asthma. Airway tissue was immunostained for tensin1. Tensin1 expression in cultured human airway smooth muscle cells (HASMCs) was evaluated using qRT-PCR, western blotting and immunofluorescent staining. siRNAs were used to downregulate tensin1 expression. Tensin1 expression was increased in the airway smooth muscle and lamina propria in COPD tissue, but not asthma, when compared to controls. Tensin1 was expressed in HASMCs and upregulated by TGFβ1. TGFβ1 and fibronectin increased the localisation of tensin1 to fibrillar adhesions. Tensin1 and α-smooth muscle actin (αSMA) were strongly co-localised, and tensin1 depletion in HASMCs attenuated both αSMA expression and contraction of collagen gels. In summary, tensin1 expression is increased in COPD airways, and may promote airway obstruction by enhancing the expression of contractile proteins and their localisation to stress fibres in HASMCs

CRTH2 expression on T cells in asthma

Mast cell-derived prostaglandin D2 (PGD2) is the major prostanoid found within the airway of asthmatics immediately following allergen challenge. PGD2 has been shown to have chemokinetic effects on eosinophils and T helper type 2 (Th2) cells in vitro. This occurs through the interaction of PGD2 with the G-protein-coupled chemokine receptor homologous molecule expressed on Th2 lymphocytes (CRTH2). The expression of CRTH2 has been shown to be highly selective for Th2 cells. Using flow cytometry we have studied the expression of CRTH2 on T cells in blood and bronchoalveolar lavage fluid in asthmatics and normal subjects. CRTH2 expression was confined to a small percentage of blood T cells in asthmatics (1·8% ± 0·2) and normal (1·6% ± 0·2) subjects. CRTH2 was enriched significantly on interleukin (IL)-4+/IL-13+ T cells compared to interferon (IFN)-γ+ T cells (P < 0·001). There was a small population of CRTH2+ T cells in the bronchoalveolar lavage (BAL) of asthmatics (2·3% ± 0·6) and normal subjects (0·3% ± 0·1), and there was a significant difference between the two groups (P < 0·05). There were similar amounts of PGD2 in the BAL of asthma and normal subjects. Within paired blood–BAL samples from the same subject there was no increase in CRTH2+ T cells in the BAL compared to blood in asthmatics. Enrichment of CRTH2 on IL-4+ and IL-13+ T cells compared to IFN-γ+ T cells was also seen in BAL from asthmatics (P < 0·001). CRTH2 is expressed preferentially by IL-4+/IL-13+ T cells compared to IFN-γ+ T cells. However, given their small numbers they are unlikely to have a significant involvement in the pathogenesis of asthma. CRTH2 antagonism may not diminish T cell accumulation in the asthmatic lung

Using fractional exhaled nitric oxide (FeNO) to diagnose steroid-responsive disease and guide asthma management in routine care

Acknowledgements We thank Robin Taylor for his informative thinking and publications on FeNO, which have helped to influence and direct the thinking of the authors. Funding Extraction of the real-life dataset was funded by Research in Real Life Limited, the analysis of the dataset and the writing of this manuscript were co-funded (50:50) by Research in Real Life Limited and Aerocrine.Peer reviewedPublisher PD

Pathophysiological regulation of lung function by the free fatty acid receptor FFA4.

Increased prevalence of inflammatory airway diseases including asthma and chronic obstructive pulmonary disease (COPD) together with inadequate disease control by current frontline treatments means that there is a need to define therapeutic targets for these conditions. Here, we investigate a member of the G protein-coupled receptor family, FFA4, that responds to free circulating fatty acids including dietary omega-3 fatty acids found in fish oils. We show that FFA4, although usually associated with metabolic responses linked with food intake, is expressed in the lung where it is coupled to Gq/11 signaling. Activation of FFA4 by drug-like agonists produced relaxation of murine airway smooth muscle mediated at least in part by the release of the prostaglandin E2 (PGE2) that subsequently acts on EP2 prostanoid receptors. In normal mice, activation of FFA4 resulted in a decrease in lung resistance. In acute and chronic ozone models of pollution-mediated inflammation and house dust mite and cigarette smoke-induced inflammatory disease, FFA4 agonists acted to reduce airway resistance, a response that was absent in mice lacking expression of FFA4. The expression profile of FFA4 in human lung was similar to that observed in mice, and the response to FFA4/FFA1 agonists similarly mediated human airway smooth muscle relaxation ex vivo. Our study provides evidence that pharmacological targeting of lung FFA4, and possibly combined activation of FFA4 and FFA1, has in vivo efficacy and might have therapeutic value in the treatment of bronchoconstriction associated with inflammatory airway diseases such as asthma and COPD

Impaired Mitochondrial Microbicidal Responses in Chronic Obstructive Pulmonary Disease Macrophages

RATIONALE: Chronic obstructive pulmonary disease (COPD) is characterized by impaired clearance of pulmonary bacteria. OBJECTIVES: The effect of COPD on alveolar macrophage (AM) microbicidal responses was investigated. METHODS: Alveolar macrophages (AMs) were obtained from bronchoalveolar lavage from healthy donors or COPD patients and challenged with opsonized serotype 14 Streptococcus pneumoniae. Cells were assessed for apoptosis, bactericidal activity and mitochondrial reactive oxygen species (mROS) production. A transgenic mouse line, in which the CD68 promoter ensures macrophage specific expression of human Mcl-1 (CD68.hMcl-1), was used to model the molecular aspects of COPD. MEASUREMENTS AND MAIN RESULTS: COPD AM had elevated levels of Mcl-1, an anti-apoptotic Bcl-2 family member, with selective reduction of delayed intracellular bacterial killing. CD68.hMcl-1 AM phenocopied the microbicidal defect since transgenic mice demonstrated impaired clearance of pulmonary bacteria and increased neutrophilic inflammation. Murine bone marrow-derived macrophages (BMDM) and human monocyte-derived macrophages (MDM) generated mitochondrial reactive oxygen species (mROS) in response to pneumococci, which co-localized with bacteria and phagolysosomes to enhance bacterial killing. The Mcl-1 transgene increased oxygen consumption rates and mROS expression in mock-infected BMDM but reduced caspase-dependent mROS production after pneumococcal challenge. COPD AM also increased basal mROS expression, but failed to increase production after pneumococcal challenge, in keeping with reduced intracellular bacterial killing. The defect in COPD AM intracellular killing was associated with a reduced ratio of mROS /superoxide dismutase 2. CONCLUSIONS: Upregulation of Mcl-1 and chronic adaption to oxidative stress alters mitochondrial metabolism and microbicidal function, reducing the delayed phase of intracellular bacterial clearance in COPD

Genome-wide association study of thyroid-stimulating hormone highlights new genes, pathways and associations with thyroid disease.

Thyroid hormones play a critical role in regulation of multiple physiological functions and thyroid dysfunction is associated with substantial morbidity. Here, we use electronic health records to undertake a genome-wide association study of thyroid-stimulating hormone (TSH) levels, with a total sample size of 247,107. We identify 158 novel genetic associations, more than doubling the number of known associations with TSH, and implicate 112 putative causal genes, of which 76 are not previously implicated. A polygenic score for TSH is associated with TSH levels in African, South Asian, East Asian, Middle Eastern and admixed American ancestries, and associated with hypothyroidism and other thyroid disease in South Asians. In Europeans, the TSH polygenic score is associated with thyroid disease, including thyroid cancer and age-of-onset of hypothyroidism and hyperthyroidism. We develop pathway-specific genetic risk scores for TSH levels and use these in phenome-wide association studies to identify potential consequences of pathway perturbation. Together, these findings demonstrate the potential utility of genetic associations to inform future therapeutics and risk prediction for thyroid diseases

Corrigendum to: Cohort profile: Extended Cohort for E-health, Environment and DNA (EXCEED)

This is a correction to: International Journal of Epidemiology, Volume 48, Issue 3, June 2019, Pages 678–679j, https://doi.org/10.1093/ije/dyz07

A novel electrospun biphasic scaffold provides optimal three-dimensional topography forin vitroco-culture of airway epithelial and fibroblast cells

Conventional airway in vitro models focus upon the function of individual structural cells cultured in a two-dimensional monolayer, with limited three-dimensional (3D) models of the bronchial mucosa. Electrospinning offers an attractive method to produce defined, porous 3D matrices for cell culture. To investigate the effects of fibre diameter on airway epithelial and fibroblast cell growth and functionality, we manipulated the concentration and deposition rate of the non-degradable polymer polyethylene terephthalate to create fibres with diameters ranging from nanometre to micrometre. The nanofibre scaffold closely resembles the basement membrane of the bronchiole mucosal layer, and epithelial cells cultured at the air–liquid interface on this scaffold showed polarized differentiation. The microfibre scaffold mimics the porous sub-mucosal layer of the airway into which lung fibroblast cells showed good penetration. Using these defined electrospinning parameters we created a biphasic scaffold with 3D topography tailored for optimal growth of both cell types. Epithelial and fibroblast cells were co-cultured onto the apical nanofibre phase and the basal microfibre phase respectively, with enhanced epithelial barrier formation observed upon co-culture. This biphasic scaffold provides a novel 3D in vitro platform optimized to mimic the different microenvironments the cells encounter in vivo on which to investigate key airway structural cell interactions in airway diseases such as asthma

Acute blood biomarker profiles predict cognitive deficits 6 and 12 months after COVID-19 hospitalization

Post-COVID cognitive deficits, including ‘brain fog’, are clinically complex, with both objective and subjective components. They are common and debilitating, and can affect the ability to work, yet their biological underpinnings remain unknown. In this prospective cohort study of 1,837 adults hospitalized with COVID-19, we identified two distinct biomarker profiles measured during the acute admission, which predict cognitive outcomes 6 and 12 months after COVID-19. A first profile links elevated fibrinogen relative to C-reactive protein with both objective and subjective cognitive deficits. A second profile links elevated D-dimer relative to C-reactive protein with subjective cognitive deficits and occupational impact. This second profile was mediated by fatigue and shortness of breath. Neither profile was significantly mediated by depression or anxiety. Results were robust across secondary analyses. They were replicated, and their specificity to COVID-19 tested, in a large-scale electronic health records dataset. These findings provide insights into the heterogeneous biology of post-COVID cognitive deficits