33 results found
Ombredane HCJ, Fenwick PS, Barnes PJ, et al., 2023, Temporal Release of IL-1 Family Members from Virally Infected Airway Epithelial Cells Suggests IL-36γ Is the Early Responder, AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY, Vol: 68, Pages: 339-341, ISSN: 1044-1549
Baker JR, Fenwick PS, Koss CK, et al., 2022, Imbalance between IL-36 receptor agonist and antagonist drives neutrophilic inflammation in COPD, JCI Insight, Vol: 7, ISSN: 2379-3708
Current treatments fail to modify the underlying pathophysiology and disease progression of chronic obstructive pulmonary disease (COPD), necessitating alternative therapies. Here, we show that COPD subjects have increased IL-36γ and decreased IL-36 receptor antagonist (IL-36Ra) in bronchoalveolar and nasal fluid compared to control subjects. IL-36γ is derived from small airway epithelial cells (SAEC) and further induced by a viral mimetic, whereas IL-36RA is derived from macrophages. IL-36γ stimulates release of the neutrophil chemoattractants CXCL1 and CXCL8, as well as elastolytic matrix metalloproteinases (MMPs) from small airway fibroblasts (SAF). Proteases released from COPD neutrophils cleave and activate IL-36γ thereby perpetuating IL-36 inflammation. Transfer of culture media from SAEC to SAF stimulated release of CXCL1, that was inhibited by exogenous IL-36RA. The use of a therapeutic antibody that inhibits binding to the IL-36 receptor (IL-36R) attenuated IL-36γ driven inflammation and cellular cross talk. We have demonstrated a mechanism for the amplification and propagation of neutrophilic inflammation in COPD and that blocking this cytokine family via a IL-36R neutralizing antibody could be a promising new therapeutic strategy in the treatment of COPD.
Baker JR, Fenwick PS, Owles HB, et al., 2021, IL-36? - a key mediator of neutrophilic inflammation in chronic obstructive pulmonary disease, European-Respiratory-Society (ERS) International Congress, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Singh R, Belchamber K, Fenwick P, et al., 2021, Defective monocyte-derived macrophage phagocytosis is associated with exacerbation frequency in COPD, Respiratory Research, Vol: 22, Pages: 1-11, ISSN: 1465-9921
BackgroundLower airway bacterial colonisation (LABC) in COPD patients is associated with increased exacerbation frequency and faster lung function decline. Defective macrophage phagocytosis in COPD drives inflammation, but how defective macrophage function contributes to exacerbations is not clear. This study investigated the association between macrophage phagocytosis and exacerbation frequency, LABC and clinical parameters.MethodsMonocyte-derived macrophages (MDM) were generated from 92 stable COPD patients, and at the onset of exacerbation in 39 patients. Macrophages were exposed to fluorescently labelled Haemophilus influenzae or Streptococcus pneumoniae for 4 h, then phagocytosis measured by fluorimetry and cytokine release by ELISA. Sputum bacterial colonisation was measured by PCR.ResultsPhagocytosis of H. influenzae was negatively correlated with exacerbation frequency (r = 0.440, p < 0.01), and was significantly reduced in frequent vs. infrequent exacerbators (1.9 × 103 RFU vs. 2.5 × 103 RFU, p < 0.01). There was no correlation for S. pneumoniae. There was no association between phagocytosis of either bacteria with age, lung function, smoking history or treatment with inhaled corticosteroids, or long-acting bronchodilators. Phagocytosis was not altered during an exacerbation, or in the 2 weeks post-exacerbation. In response to phagocytosis, MDM from exacerbating patients showed increased release of CXCL-8 (p < 0.001) and TNFα (p < 0.01) compared to stable state.ConclusionImpaired COPD macrophage phagocytosis of H. influenzae, but not S. pneumoniae is associated with exacerbation frequency, resulting in pro-inflammatory macrophages that may contribute to disease progression. Targeting these frequent exacerbators with drugs that improve macrophage phagocytosis may prove beneficial.
Finney L, Glanville N, Farne H, et al., 2021, Inhaled corticosteroids downregulate the SARS-CoV-2 receptor ACE2 in COPD through suppression of type I interferon, Journal of Allergy and Clinical Immunology, Vol: 147, Pages: 510-519.e5, ISSN: 0091-6749
Background: The mechanisms underlying altered susceptibility and propensity to severe Coronavirus disease 2019 (COVID-19) disease in at-risk groups such as patients with chronic obstructive pulmonary disease (COPD) are poorly understood. Inhaled corticosteroids (ICS) are widely used in COPD but the extent to which these therapies protect or expose patients to risk of severe COVID-19 is unknown. Objective: The aim of this study was to evaluate the effect of ICS upon pulmonary expression of the SARS-CoV-2 viral entry receptor angiotensin-converting enzyme (ACE)-2.Methods: We evaluated the effect of ICS administration upon pulmonary ACE2 expression in vitro in human airway epithelial cell cultures and in vivo in mouse models of ICS administration. Mice deficient in the type I interferon-α/β receptor (Ifnar1−/−) and exogenous interferon-β administration experiments were used to study the functional role of type-I IFN signalling in ACE2 expression. We compared sputum ACE2 expression in patients with COPD stratified according to use or non-use of ICS.ResultsICS administration attenuated ACE2 expression in mice, an effect that was reversed by exogenous interferon-β administration and Ifnar1−/− mice had reduced ACE2 expression, indicating that type I interferon contributes mechanistically to this effect. ICS administration attenuated expression of ACE2 in COPD airway epithelial cell cultures and in mice with elastase-induced COPD-like changes. COPD patients taking ICS also had reduced sputum expression of ACE2 compared to non-ICS users.Conclusion: ICS therapies in COPD reduce expression of the SARS-CoV-2 entry receptor ACE2. This effect may thus contribute to altered susceptibility to COVID-19 in patients with COPD.
Singanayagam A, Glanville N, Cuthbertson L, et al., 2019, Inhaled corticosteroid suppression of cathelicidin drives dysbiosis and bacterial infection in chronic obstructive pulmonary disease, Science Translational Medicine, Vol: 11, Pages: 1-13, ISSN: 1946-6234
Bacterial infection commonly complicates inflammatory airway diseases such as chronic obstructive pulmonary disease (COPD). The mechanisms of increased infection susceptibility and how use of the commonly prescribed therapy inhaled corticosteroids (ICS) accentuates pneumonia risk in COPD are poorly understood. Here, using analysis of samples from patients with COPD, we show that ICS use is associated with lung microbiota disruption leading to proliferation of streptococcal genera, an effect that could be recapitulated in ICS-treated mice. To study mechanisms underlying this effect, we used cellular and mouse models of streptococcal expansion with Streptococcus pneumoniae, an important pathogen in COPD, to demonstrate that ICS impairs pulmonary clearance of bacteria through suppression of the antimicrobial peptide cathelicidin. ICS impairment of pulmonary immunity was dependent on suppression of cathelicidin because ICS had no effect on bacterial loads in mice lacking cathelicidin (Camp-/-) and exogenous cathelicidin prevented ICS-mediated expansion of streptococci within the microbiota and improved bacterial clearance. Suppression of pulmonary immunity by ICS was mediated by augmentation of the protease cathepsin D. Collectively, these data suggest a central role for cathepsin D/cathelicidin in the suppression of antibacterial host defense by ICS in COPD. Therapeutic restoration of cathelicidin to boost antibacterial immunity and beneficially modulate the lung microbiota might be an effective strategy in COPD.
Finney LJ, Belchamber KBR, Fenwick PS, et al., 2019, Human rhinovirus impairs the innate immune response to bacteria in alveolar macrophages in chronic obstructive pulmonary disease, American Journal of Respiratory and Critical Care Medicine, Vol: 199, Pages: 1496-1507, ISSN: 1073-449X
Rationale Human rhinovirus (HRV) is a common cause of COPD exacerbations. Secondary bacterial infection is associated with more severe symptoms and delayed recovery. Alveolar macrophages clear bacteria from the lung and maintain lung homeostasis through cytokine secretion. These processes are defective in COPD. The effect of HRV on macrophage function is unknown. Objectives To investigate the effect of HRV on phagocytosis and cytokine response to bacteria by alveolar macrophages and monocyte derived macrophages (MDM) in COPD and healthy controls. Methods Alveolar macrophages were obtained by bronchoscopy and MDM by adherence. Macrophages were exposed to HRV 16 (multiplicity of infection 5), polyI:C 30μg/ml, interferon (IFN)-β 10μg/ml, IFN-γ 10μg/ml or medium control for 24 hours. Phagocytosis of fluorescently-labelled Haemophilus influenzae or Streptococcus pneumoniae was assessed by fluorimetry. CXCL8, TNF and IL-10 release was measured by ELISA. Main Results HRV significantly impaired phagocytosis of H. influenzae by 23% in MDM (n=37) and 18% in alveolar macrophages (n=20) in COPD. HRV also significantly reduced phagocytosis of S. pneumoniae by 33% in COPD MDM. There was no effect in healthy controls. Phagocytosis of H. influenzae was impaired by polyI:C but not IFN-β or IFN-γ. HRV significantly reduced cytokine responses to H. influenzae. The IL-10 response to H. influenzae was significantly impaired by polyI:C, IFN-β and IFN-γ. Conclusions HRV impairs phagocytosis of bacteria in COPD which may lead to an outgrowth of bacteria. HRV also impairs cytokine responses to bacteria via the TLR3/IFN pathway which may prevent resolution of inflammation leading to prolonged exacerbations in COPD.
Dunne A, Kawamatawong T, Fenwick P, et al., 2019, Direct inhibitory rffect of the phosphodiesterase-4 inhibitor, roflumilast, on neutrophil migration in COPD, American Journal of Respiratory Cell and Molecular Biology, Vol: 60, Pages: 445-453, ISSN: 1044-1549
Neutrophilic inflammation is characteristic of COPD, yet there are no effective anti-inflammatory therapies. The phosphodiesterase (PDE)4 inhibitor, roflumilast is approved for use in COPD and suppresses sputum neutrophilia. The mechanism underlying this observation is unclear and therefore this study addressed whether roflumilast directly affected neutrophil migration. Blood-derived neutrophils were isolated from non-smokers, smokers and COPD patients and chemotaxis measured using Boyden chambers. Intracellular calcium ion concentration ([Ca2+]i) was measured by fluorimetry and shape change and CD11b expression by flow cytometry. Neutrophils from COPD patients showed enhanced chemotactic responses towards both CXCL1 and LTB4 compared with control cells. Chemotaxis was inhibited by both the active metabolite, roflumilast-N-oxide, and rolipram in a concentration-dependent manner with no difference in responsiveness between subjects. Roflumilast-N-oxide and rolipram were less efficacious against CXCL1 and LTB4-mediated [Ca2+]i suggesting that inhibition was not via this pathway. Both PDE4 inhibitors attenuated chemoattractant-mediated shape change and CD11b up-regulation suggesting common mechanisms. The stable cAMP analogue, 8-Br-cAMP, inhibited chemotaxis, as did the direct Epac1 activator 8-pCPT-2’-O-Me-cAMP but not the direct PKA activator, 6-Bnz-cAMP. These data suggest that roflumilast inhibits neutrophil chemotaxis directly via a cAMP-mediated mechanism requiring activation of Epac1, and that Epac1 activators could reduce COPD neutrophilic inflammation.
Baker J, Fenwick PS, Tilman J, et al., 2019, IL-36 gamma is Released from Small Airway Epithelial Cells and Drives Macrophage Inflammation in COPD, International Conference of the American-Thoracic-Society, Publisher: AMER THORACIC SOC, ISSN: 1073-449X
Baker J, Vuppusetty C, Colley T, et al., 2018, MicroRNA-570 is a novel regulator of cellular senescence and inflammaging, FASEB Journal, ISSN: 0892-6638
Diseases of accelerated aging often occur together (multimorbidity), and their prevalence is increasing, with high societal and health care costs. Chronic obstructive pulmonary disease (COPD) is one such condition, in which one half of patients exhibit ≥4 age-related diseases. Diseases of accelerated aging share common molecular pathways, which lead to the detrimental accumulation of senescent cells. These senescent cells no longer divide but release multiple inflammatory proteins, known as the senescence-associated secretory phenotype, which may perpetuate and speed disease. Here, we show that inhibiting miR-570-3p, which is increased in COPD cells, reverses cellular senescence by restoring the antiaging molecule sirtuin-1. MiR-570-3p is induced by oxidative stress in airway epithelial cells through p38 MAP kinase-c-Jun signaling and drives senescence by inhibiting sirtuin-1. Inhibition of elevated miR-570-3p in COPD small airway epithelial cells, using an antagomir, restores sirtuin-1 and suppresses markers of cellular senescence (p16INK4a, p21Waf1, and p27Kip1), thereby restoring cellular growth by allowing progression through the cell cycle. MiR-570-3p inhibition also suppresses the senescence-associated secretory phenotype (matrix metalloproteinases-2/9, C-X-C motif chemokine ligand 8, IL-1β, and IL-6). Collectively, these data suggest that inhibiting miR-570-3p rejuvenates cells via restoration of sirtuin-1, reducing many of the abnormalities associated with cellular senescence.—Baker, J. R., Vuppusetty, C., Colley, T., Hassibi, S., Fenwick, P. S., Donnelly, L. E., Ito, K., Barnes, P. J. MicroRNA-570 is a novel regulator of cellular senescence and inflammaging.
Yanagisawa S, Baker JR, Vuppusetty C, et al., 2018, The dynamic shuttling of SIRT1 between cytoplasm and nuclei in bronchial epithelial cells by single and repeated cigarette smoke exposure, PLoS ONE, Vol: 13, ISSN: 1932-6203
SIRT1 (silent information regulator 2 homolog 1) is a crucial cellular survival protein especially in oxidative stress environments, and has been thought to locate within the nuclei, but also known to shuttle between cytoplasm and nuclei in some cell types. Here, we show for the first time the dynamics of SIRT1 in the presence of single or concurrent cigarette smoke extract (CSE) exposure in human bronchial epithelial cells (HBEC). In BEAS-2B HBEC or primary HBEC, SIRT1 was localized predominantly in cytoplasm, and the CSE (3%) induced nuclear translocation of SIRT1 from cytoplasm in the presence of L-buthionine sulfoximine (an irreversible inhibitor of γ-glutamylcystein synthetase), mainly through the activation of phosphatidylinositol 3-kinase (PI3K) α subunit. This SIRT1 nuclear shuttling was associated with FOXO3a nuclear translocation and the strong induction of several anti-oxidant genes including superoxide dismutase (SOD) 2 and 3; therefore seemed to be an adaptive response. When BEAS-2B cells were pretreated with repeated exposure to a lower concentration of CSE (0.3%), the CSE-induced SIRT1 shuttling and resultant SOD2/3 mRNA induction were significantly impaired. Thus, this result offers a useful cell model to mimic the impaired anti-oxidant capacity in cigarette smoking-associated lung disease such as chronic obstructive pulmonary disease.
Yanagisawa S, Baker JR, Vuppusetty C, et al., 2017, Decreased phosphatase PTEN amplifies PI3K signaling and enhances pro-inflammatory cytokine release in COPD, American Journal of Physiology-Lung Cellular and Molecular Physiology, Vol: 313, Pages: L230-L239, ISSN: 1522-1504
The phosphatidylinositol 3-kinase (PI3K) pathway is activated in chronic obstructive pulmonary disease (COPD), but the regulatory mechanisms for this pathway are yet to be elucidated. Our aim was to determine the expression and role of phosphatase and tensin homolog deleted from chromosome 10 (PTEN), a negative regulator of the PI3K pathway, in COPD. PTEN expression and activity were measured in the peripheral lung of COPD patients compared to smoking and non-smoking controls. The direct influence of cigarette smoke extract (CSE) on PTEN expression was assessed using primary lung epithelial cells and a cell line (BEAS-2B) in the presence or absence of L-buthionine-sulfoximine (BSO) to deplete intracellular glutathione. The impact of PTEN knock-down by RNA interference on cytokine production was also examined. In peripheral lung, PTEN protein was significantly decreased in patients with COPD compared to the subjects without COPD (p < 0.001), and positively correlated with the severity of air-flow obstruction (FEV1 % predicted; r = 0.50; p = 0.0012), although no difference was observed in PTEN activity. Conversely, phosphorylated Akt, as a marker of PI3K activation, showed a negative correlation with PTEN protein levels (r = -0.41; p = 0.0042). Both in primary bronchial epithelial cells and BEAS-2B cell line, CSE decreased PTEN protein, which was reversed by N-acetylcysteine treatment. PTEN knock-down potentiated Akt phosphorylation and enhanced production of pro-inflammatory cytokines, such as IL-6, CXCL8, CCL2 and CCL5. In conclusion, oxidative stress reduces PTEN protein levels, which may result in increased PI3K signaling and amplification of inflammation in COPD.
Yeo SCM, Fenwick PS, Barnes PJ, et al., 2017, Isorhapontigenin, a bioavailable dietary polyphenol, suppresses airway epithelial cell inflammation through a corticosteroid-independent mechanism, British Journal of Pharmacology, Vol: 174, Pages: 2043-2059, ISSN: 1476-5381
Background and PurposeChronic obstructive pulmonary disease (COPD) is a corticosteroid-resistant airway inflammatory condition. Resveratrol has exhibited anti-inflammatory activities in COPD but has weak potency and poor pharmacokinetics. This study aims to evaluate the potential of isorhapontigenin, another dietary polyphenol, as a novel anti-inflammatory agent for COPD by examining its effects in vitro and its pharmacokinetics in vivo.Experimental ApproachPrimary human airway epithelial cells derived from healthy and COPD subjects and A549 epithelial cells were incubated with isorhapontigenin or resveratrol and stimulated with IL-1β in the presence or absence of cigarette smoke extract. Their effects on the release of IL-6 and chemokine (C-X-C motif) ligand 8 (CXCL8) were determined and the activation of NF-κB, AP-1, MAPKs and PI3K/Akt/FoxO3A pathways compared to dexamethasone were evaluated. The pharmacokinetic profiles of isorhapontigenin were assessed in Sprague-Dawley rats after respective intravenous and oral administration.Key ResultsIsorhapontigenin exhibited concentration-dependent inhibition of IL-6 and CXCL8 release, with IC50 values at least two-fold lower than resveratrol. These were associated with suppressed NF-κB and AP-1 activation and notably, the PI3K/Akt/FoxO3A pathway that was relatively insensitive to dexamethasone. In vivo, isorhapontigenin was rapidly absorbed with abundant plasma exposure after oral dosing. Its oral bioavailability was approximately 50% higher than resveratrol.Conclusions and ImplicationsIsorhapontigenin, an orally bioavailable dietary polyphenol, displayed superior anti-inflammatory effects compared to resveratrol. Furthermore, it suppressed the PI3K/Akt pathway that is insensitive to corticosteroids. These favourable efficacy and pharmacokinetic properties support its further development as a novel anti-inflammatory agent for COPD.
Baker JR, Vuppusetty C, Colley T, et al., 2016, Oxidative stress dependent microRNA-34a activation via PI3Kα reduces the expression of sirtuin-1 and sirtuin-6 in epithelial cells, Scientific Reports, Vol: 6, ISSN: 2045-2322
Sirtuin-1 (SIRT1) and SIRT6, NAD(+)-dependent Class III protein deacetylases, are putative anti-aging enzymes, down-regulated in patients with chronic obstructive pulmonary disease (COPD), which is characterized by the accelerated ageing of the lung and associated with increased oxidative stress. Here, we show that oxidative stress (hydrogen peroxide) selectively elevates microRNA-34a (miR-34a) but not the related miR-34b/c, with concomitant reduction of SIRT1/-6 in bronchial epithelial cells (BEAS2B), which was also observed in peripheral lung samples from patients with COPD. Over-expression of a miR-34a mimic caused a significant reduction in both mRNA and protein of SIRT1/-6, whereas inhibition of miR-34a (antagomir) increased these sirtuins. Induction of miR-34a expression with H2O2 was phosphoinositide-3-kinase (PI3K) dependent as it was associated with PI3Kα activation as well as phosphatase and tensin homolog (PTEN) reduction. Importantly, miR-34a antagomirs increased SIRT1/-6 mRNA levels, whilst decreasing markers of cellular senescence in airway epithelial cells from COPD patients, suggesting that this process is reversible. Other sirtuin isoforms were not affected by miR-34a. Our data indicate that miR-34a is induced by oxidative stress via PI3K signaling, and orchestrates ageing responses under oxidative stress, therefore highlighting miR-34a as a new therapeutic target and biomarker in COPD and other oxidative stress-driven aging diseases.
Costa C, Traves S, Tudhope SJ, et al., 2016, Enhanced monocyte migration to CXCR3 and CCR5 chemokines in COPD, European Respiratory Journal, Vol: 47, ISSN: 1399-3003
Chronic obstructive pulmonary disease (COPD) patients exhibit chronic inflammation, both in the lung parenchyma and the airways, which is characterised by an increased infiltration of macrophages and T-lymphocytes, particularly CD8+ cells. Both cell types can express chemokine (C-X-C motif) receptor (CXCR)3 and C-C chemokine receptor 5 and the relevant chemokines for these receptors are elevated in COPD. The aim of this study was to compare chemotactic responses of lymphocytes and monocytes of nonsmokers, smokers and COPD patients towards CXCR3 ligands and chemokine (C-C motif) ligand (CCL)5.Migration of peripheral blood mononuclear cells, monocytes and lymphocytes from nonsmokers, smokers and COPD patients toward CXCR3 chemokines and CCL5 was analysed using chemotaxis assays.There was increased migration of peripheral blood mononuclear cells from COPD patients towards all chemokines studied when compared with nonsmokers and smokers. Both lymphocytes and monocytes contributed to this enhanced response, which was not explained by increased receptor expression. However, isolated lymphocytes failed to migrate and isolated monocytes from COPD patients lost their enhanced migratory capacity.Both monocytes and lymphocytes cooperate to enhance migration towards CXCR3 chemokines and CCL5. This may contribute to increased numbers of macrophages and T-cells in the lungs of COPD patients, and inhibition of recruitment using selective antagonists might be a treatment to reduce the inflammatory response in COPD.
Yeo SCM, Fenwick PS, Barnes PJ, et al., 2015, Anti-inflammatory effects of resveratrol analogues in cellular models of airway inflammation, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Fenwick PS, Macedo P, Barnes PJ, et al., 2015, Effect of JAK inhibitors on release of CXCL9, CXCL10 and CXCL11 from human airway epithelial cells, PLOS One, Vol: 10, ISSN: 1932-6203
BackgroundCD8+ T-cells are located in the small airways of COPD patients and may contribute to pathophysiology. CD8+ cells express the chemokine receptor, CXCR3 that binds CXCL9, CXCL10 and CXCL11, which are elevated in the airways of COPD patients. These chemokines are released from airway epithelial cells via activation of receptor associated Janus kinases (JAK). This study compared the efficacy of two structurally dissimilar pan-JAK inhibitors, PF956980 and PF1367550, and the glucocorticosteroid dexamethasone, in BEAS-2B and human primary airway epithelial cells from COPD patients and control subjects.MethodsCells were stimulated with either IFNγ alone or with TNFα, and release of CXCL9, CXCL10 and CXCL11 measured by ELISA and expression of CXCL9, CXCL10 and CXCL11 by qPCR. Activation of JAK signalling was assessed by STAT1 phosphorylation and DNA binding.ResultsThere were no differences in the levels of release of CXCL9, CXCL10 and CXCL11 from primary airway epithelial cells from any of the subjects or following stimulation with either IFNγ alone or with TNFα. Dexamethasone did not inhibit CXCR3 chemokine release from stimulated BEAS-2B or primary airway epithelial cells. However, both JAK inhibitors suppressed this response with PF1367550 being ~50-65-fold more potent than PF956980. The response of cells from COPD patients did not differ from controls with similar responses regardless of whether inhibitors were added prophylactically or concomitant with stimuli. These effects were mediated by JAK inhibition as both compounds suppressed STAT1 phosphorylation and DNA-binding of STAT1 and gene transcription.ConclusionsThese data suggest that the novel JAK inhibitor, PF1367550, is more potent than PF956980 and that JAK pathway inhibition in airway epithelium could provide an alternative anti-inflammatory approach for glucocorticosteroid-resistant diseases including COPD.
Iiott NE, Heward JA, Roux B, et al., 2014, Long non-coding RNAs and enhancer RNAs regulate the lipopolysaccharide-induced inflammatory response in human monocytes, Nature Communications, Vol: 5, Pages: 1-14, ISSN: 2041-1723
Early reports indicate that long non-coding RNAs (lncRNAs) are novel regulators of biological responses. However, their role in the human innate immune response, which provides the initial defence against infection, is largely unexplored. To address this issue, here we characterize the long non-coding RNA transcriptome in primary human monocytes using RNA sequencing. We identify 76 enhancer RNAs (eRNAs), 40 canonical lncRNAs, 65 antisense lncRNAs and 35 regions of bidirectional transcription (RBT) that are differentially expressed in response to bacterial lipopolysaccharide (LPS). Crucially, we demonstrate that knockdown of nuclear-localized, NF-κB-regulated, eRNAs (IL1β-eRNA) and RBT (IL1β-RBT46) surrounding the IL1β locus, attenuates LPS-induced messenger RNA transcription and release of the proinflammatory mediators, IL1β and CXCL8. We predict that lncRNAs can be important regulators of the human innate immune response.
Chana KK, Fenwick PS, Nicholson AG, et al., 2013, Identiﬁcation of a distinct glucocorticosteroid-insensitive pulmonary macrophage phenotype in patients with chronic obstructive pulmonary disease, Journal of Allergy and Clinical Immunology, ISSN: 0091-6749
BackgroundIn patients with chronic obstructive pulmonary disease (COPD), pulmonary macrophages increase in number, release increased levels of inflammatory mediators, and respond poorly to glucocorticosteroids. Whether this is due to a change in macrophage phenotype or localized activation is unknown.ObjectiveWe sought to investigate whether macrophages from patients with COPD are a distinct phenotype.MethodsMacrophage populations were isolated from human lung tissue from nonsmokers, smokers, and patients with COPD by using Percoll density gradients. Five macrophage populations were isolated on the basis of density (1.011-1.023, 1.023-1.036, 1.036-1.048, 1.048-1.061, and 1.061-1.073 g/mL), and cell-surface expression of CD14, CD16, CD163, CD40, and CD206 was assessed by using flow cytometry. Release of active matrix metalloproteinase 9, TNF-α, CXCL8, and IL-10 was measured by using ELISA.ResultsThe 2 least dense fractions were more than 90% apoptotic/necrotic, with the remaining fractions greater than 70% viable. Macrophages from nonsmokers and smokers were CD163+, CD206+, CD14+, and CD40−, whereas macrophages from patients with COPD were less defined, showing significantly lower expression of all receptors. There were no differences in receptor expression associated with density. Macrophages from patients with COPD of a density of 1.036 to 1.048 g/mL released higher levels of active matrix metalloproteinase 9 compared with cells from nonsmokers, with no difference between the remaining fractions. This population of macrophages from patients with COPD was less responsive to budesonide compared with those from nonsmokers and smokers when stimulated with LPS. Glucocorticosteroid insensitivity was selective for proinflammatory cytokines because budesonide inhibition of LPS-stimulated IL-10 release was similar for all macrophages.ConclusionsThis study identifies a specific macrophage phenotype in the lungs of patients with COPD who are glucocorticosteroid in
Koarai A, Traves SL, Fenwick PS, et al., 2012, Expression of muscarinic receptors by human macrophages., Eur Respir J, Vol: 39, Pages: 698-704
Macrophages increase in number and are highly activated in chronic obstructive pulmonary disease (COPD). Muscarinic receptor antagonists inhibit acetylcholine-stimulated release of neutrophilic chemoattractants, suggesting that acetylcholine may regulate macrophage responses. Therefore, expression and function of components of the non-neuronal cholinergic system in monocyte-macrophage cells was investigated. RNA was isolated from monocytes, monocyte-derived macrophages (MDMs), lung and alveolar macrophages from nonsmokers, smokers and COPD patients, and expression of the high-affinity choline transporter, choline acetyltransferase, vesicular acetylcholine transporter and muscarinic receptors (M(1)-M(5)) ascertained using real-time PCR. M(2) and M(3) receptor expression was confirmed using immunocytochemistry. Release of interleukin (IL)-8, IL-6 and leukotriene (LT)B(4) were measured by ELISA or EIA. All monocyte-macrophage cells expressed mRNA for components of the non-neuronal cholinergic system. Lung macrophages expressed significantly more M(1) mRNA compared with monocytes, and both lung macrophages and alveolar macrophages expressed the highest levels of M(3) mRNA. Expression of M(2) and M(3) protein was confirmed in MDMs and lung macrophages. Carbachol stimulated release of LTB(4) from lung macrophages (buffer 222.3 ± 75.1 versus carbachol 1,118 ± 622.4 pg · mL(-1); n = 15, p<0.05) but not IL-6 or IL-8. LTB(4) release was attenuated by the M(3) antagonist, 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP; half maximal effective concentration 5.2 ± 2.2 nM; n = 9). Stimulation of macrophage M(3) receptors promotes release of LTB(4), suggesting that anti-muscarinic agents may be anti-inflammatory.
Pridgeon C, Bugeon L, Donnelly L, et al., 2011, Regulation of IL-17 in chronic inflammation in the human lung., Clin Sci (Lond), Vol: 120, Pages: 515-524
The regulation of human Th17 cell effector function by Treg cells (regulatory T-cells) is poorly understood. In the present study, we report that human Treg (CD4(+)CD25(+)) cells inhibit the proliferative response of Th17 cells but not their capacity to secrete IL (interleukin)-17. However, they could inhibit proliferation and cytokine production by Th1 and Th2 cells as determined by IFN-γ (interferon-γ) and IL-5 biosynthesis. Currently, as there is interest in the role of IL-17-producing cells and Treg cells in chronic inflammatory diseases in humans, we investigated the presence of CD4(+)CD25(+) T-cells and IL-17 in inflammation in the human lung. Transcripts for IL-17 were expressed in mononuclear cells and purified T-cells from lung tissue of patients with chronic pulmonary inflammation and, when activated, these cells secrete soluble protein. The T-cell-specific transcription factors RORCv2 (retinoic acid-related orphan receptor Cv2; for Th17) and FOXP3 (forkhead box P3; for Treg cells) were enriched in the T-cell fraction of lung mononuclear cells. Retrospective stratification of the patient cohort into those with COPD (chronic obstructive pulmonary disease) and non-COPD lung disease revealed no difference in the expression of IL-17 and IL-23 receptor between the groups. We observed that CD4(+)CD25(+) T-cells were present in comparable numbers in COPD and non-COPD lung tissue and with no correlation between the presence of CD4(+)CD25(+) T-cells and IL-17-producing cells. These results suggest that IL-17-expressing cells are present in chronically inflamed lung tissue, but there is no evidence to support this is due to the recruitment or expansion of Treg cells.
Mercado N, Thimmulappa R, Thomas CM, et al., 2011, Decreased histone deacetylase 2 impairs Nrf2 activation by oxidative stress., Biochem Biophys Res Commun, Vol: 406, Pages: 292-298
Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in cellular defence against oxidative stress by inducing the expression of multiple anti-oxidant genes. However, where high levels of oxidative stress are observed, such as chronic obstructive pulmonary disease (COPD), Nrf2 activity is reduced, although the molecular mechanism for this defect is uncertain. Here, we show that down-regulation of histone deacetylase (HDAC) 2 causes Nrf2 instability, resulting in reduced anti-oxidant gene expression and increase sensitivity to oxidative stress. Although Nrf2 protein was clearly stabilized after hydrogen peroxide (H(2)O(2)) stimulation in a bronchial epithelial cell line (BEAS2B), Nrf2 stability was decreased and Nrf2 acetylation increased in the presence of an HDAC inhibitor, trichostatin A (TSA). TSA also reduced Nrf2-regulated heme-oxygenase-1 (HO-1) expression in these cells, and this was confirmed in acute cigarette-smoke exposed mice in vivo. HDAC2 knock-down by RNA interference resulted in reduced H(2)O(2)-induced Nrf2 protein stability and activity in BEAS2B cells, whereas HDAC1 knockdown had no effect. Furthermore, monocyte-derived macrophages obtained from healthy volunteers (non-smokers and smokers) and COPD patients showed a significant correlation between HDAC2 expression and Nrf2 expression (r=0.92, p<0.0001). Thus, reduced HDAC2 activity in COPD may account for increased Nrf2 acetylation, reduced Nrf2 stability and impaired anti oxidant defences.
Donnelly LE, Tudhope SJ, Fenwick PS, et al., 2010, Effects of formoterol and salmeterol on cytokine release from monocyte-derived macrophages., Eur Respir J, Vol: 36, Pages: 178-186
Pulmonary macrophages are a target for inhaled therapies. Combinations of long-acting beta(2)-agonists (LABA) and glucocorticosteroids have been developed for asthma and chronic obstructive pulmonary disease (COPD). This study examined two LABA, salmeterol and formoterol, and the glucocorticosteroid, budesonide, on cytokine release from monocyte-derived macrophages (MDM) to determine whether anti-inflammatory effects observed in patients are due to inhibition of macrophages. MDM were incubated in the absence or presence of LABA or budesonide prior to stimulation with lipopolysaccharide (LPS). Tumour necrosis factor (TNF)-alpha, granulocyte macrophage-colony stimulating factor (GM-CSF) and CXC chemokine ligand (CXCL)8 were measured by ELISA. Formoterol and salmeterol inhibited LPS-stimulated release of TNF-alpha (mean effective concentration (EC(50)) 2.4+/-1.8 and 3.5+/-2.7 nM, respectively; n = 11-16), GM-CSF (EC(50) 24.6+/-2.1 and 52.4+/-40.8 nM, respectively, n = 11-12) but not CXCL8 from LPS-stimulated MDM. Budesonide inhibited release of all three cytokines (EC(50) TNF-alpha: 1.2+/-0.4 nM; GM-CSF: 0.4+/-0.2 nM; CXCL8: 0.4+/-0.1 nM; n = 3-4). Formoterol but not salmeterol elevated cAMP in these cells. These effects were attenuated by beta-adrenoceptor antagonists, propranolol and ICI118551. Salmeterol (10(-7) M) also inhibited formoterol-induced cAMP and formoterol-mediated attenuation of cytokine release. Combining budesonide (0.3 nM) with formoterol, inhibited TNF-alpha release additively. LABA may inhibit inflammatory cytokine release from macrophages in a cAMP-independent manner and act additively with budesonide.
Renshaw J, Fenwick P, Thomas C, et al., 2009, ROLE OF MUSCARINIC RECEPTORS IN REGULATION OF NEUTROPHILIC CHEMOKINE RELEASE FROM HUMAN LUNG MACROPHAGES, Winter Meeting of the British-Thoracic-Society, Publisher: B M J PUBLISHING GROUP, Pages: A136-A136, ISSN: 0040-6376
Finney-Hayward TK, Bahra P, Li S, et al., 2009, Leukotriene B4 release by human lung macrophages via receptor- not voltage-operated Ca2+ channels., Eur Respir J, Vol: 33, Pages: 1105-1112
Increased numbers of macrophages and neutrophils in the lung is a key feature of chronic obstructive pulmonary disease (COPD). The major neutrophil chemotactic agent in the airways of COPD patients is leukotriene (LT)B(4) and is released by macrophages. The present study examines the role and mechanism of Ca(2+) in platelet-activating factor (PAF)-stimulated LTB(4) release from human lung macrophages. Macrophages were isolated from lung tissue of subjects undergoing lung resection surgery and monocyte-derived macrophages (MDM) were obtained from nonsmokers, smokers without obstruction and COPD patients. Cells were stimulated with PAF and LTB(4) release and [Ca(2+)](i) was measured. Lung macrophages and MDM released LTB(4) following stimulation with PAF (mean effective concentration: 0.08+/-0.06 microM (n = 5) versus 0.17+/-0.12 microM (n = 17), respectively). Compared with MDM, lung macrophages released approximately eight-fold more LTB(4). Neither smoking nor COPD altered MDM responses. PAF-stimulated LTB(4) release was abrogated by ethylene glycol tetraacetic acid suggesting a role for extracellular Ca(2+). This was substantiated by using store-operated channel blockers econazole, SK&F96365 and Gd(3+). However, econazole and SK&F96365 were more effective in MDM than lung macrophages. Neither LOE908 nor nifedipine could attenuate this response. These data suggest that platelet-activating factor-stimulated leukotriene B(4) release from human lung macrophages is mediated, in part, by Ca(2+) influx through receptor- but not voltage-operated Ca(2+) channels.
Tudhope SJ, Catley MC, Fenwick PS, et al., 2007, The role of IkappaB kinase 2, but not activation of NF-kappaB, in the release of CXCR3 ligands from IFN-gamma-stimulated human bronchial epithelial cells., J Immunol, Vol: 179, Pages: 6237-6245, ISSN: 0022-1767
The severity of chronic obstructive pulmonary disease correlates with increased numbers of cytotoxic CD8(+) T lymphocytes in the lung parenchyma. CD8(+) T lymphocytes release IFN-gamma which stimulates airway epithelial cells to produce CXCR3 chemokines leading to further recruitment of CD8(+) T lymphocytes. To evaluate the signaling pathways involved in regulation of CXCR3 ligands, the human bronchial epithelial cell line BEAS-2B was stimulated with IFN-gamma and the release of the CXCR3 ligands was measured by ELISA. The release of CXCL9, CXCL10, and CXCL11 was inhibited by an IkappaB kinase 2 (IKK2) selective inhibitor 2-[(Aminocarbonyl)amino]-5-[4-fluorophenyl]-3-thiophenecarboxamide (TPCA-1) (EC(50) values were 0.50 +/- 0.03, 0.17 +/- 0.06, and 0.45 +/- 0.10 microM, respectively (n = 6)) and an IKK1/2 selective inhibitor 2-amino-6-(2'cyclopropylemethoxy-6'-hydroxy-phenyl)-4-piperidin-3-yl-pyridine-3-carbonitrile (EC(50) values 0.74 +/- 0.40, 0.27 +/- 0.06, and 0.88 +/- 0.29 microM, respectively (n = 6)). The glucocorticosteroid dexamethasone had no effect on CXCR3 ligand release. The release of CXCL10 was most sensitive to inhibition by IKK2 and a role for IKK2 in CXCL10 release was confirmed by overexpression of dominant-negative adenoviral constructs to IKK2 (68.2 +/- 8.3% n = 5), but not of IKK1. Neither phosphorylation of IkappaBalpha, translocation of p65 to the nucleus, or activation of a NF-kappaB-dependent reporter (Ad-NF-kappaB-luc) were detected following stimulation of BEAS-2B cells with IFN-gamma. These data suggest that IKK2 is also involved in the IFN-gamma-stimulated release of the CXCR3 ligands through a novel mechanism that is independent NF-kappaB.
Smith SJ, Fenwick PS, Nicholson AG, et al., 2006, Inhibitory effect of p38 mitogen-activated protein kinase inhibitors on cytokine release from human macrophages, BRITISH JOURNAL OF PHARMACOLOGY, Vol: 149, Pages: 393-404, ISSN: 0007-1188
Smith SJ, Cieslinski LB, Newton R, et al., 2004, Discovery of BRL 50481 [3-(N,N-dimethylsulfonamido)-4-methyl-nitrobenzene], a selective inhibitor of phosphodiesterase 7: In vitro studies in human monocytes, lung macrophages, and CD8(+) T-lymphocytes, MOLECULAR PHARMACOLOGY, Vol: 66, Pages: 1679-1689, ISSN: 0026-895X
Donnelly LE, Newton R, Kennedy GE, et al., 2004, Anti-inflammatory effects of resveratrol in lung epithelial cells: molecular mechanisms, AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY, Vol: 287, Pages: L774-L783, ISSN: 1040-0605
Culpitt SV, Rogers DF, Fenwick PS, et al., 2003, Inhibition by red wine extract, resveratrol, of cytokine release by alveolar macrophages in COPD., Thorax, Vol: 58, Pages: 942-946, ISSN: 0040-6376
The pathophysiology of chronic obstructive pulmonary disease (COPD) features pulmonary inflammation with a predominant alveolar macrophage involvement. Bronchoalveolar macrophages from patients with COPD release increased amounts of inflammatory cytokines in vitro, an effect that is not inhibited by the glucocorticosteroid dexamethasone. Resveratrol (3,5,4'-trihydroxystilbene) is a component of red wine extract that has anti-inflammatory and antioxidant properties. A study was undertaken to determine whether or not resveratrol would inhibit cytokine release in vitro by alveolar macrophages from patients with COPD.
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