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  1. Article ; Online: Previous Influenza Infection Exacerbates Allergen Specific Response and Impairs Airway Barrier Integrity in Pre-Sensitized Mice

    Kevin Looi / Alexander N. Larcombe / Kara L. Perks / Luke J. Berry / Graeme R. Zosky / Paul Rigby / Darryl A. Knight / Anthony Kicic / Stephen M. Stick

    International Journal of Molecular Sciences, Vol 22, Iss 8790, p

    2021  Volume 8790

    Abstract: In this study we assessed the effects of antigen exposure in mice pre-sensitized with allergen following viral infection on changes in lung function, cellular responses and tight junction expression. Female BALB/c mice were sensitized to ovalbumin and ... ...

    Abstract In this study we assessed the effects of antigen exposure in mice pre-sensitized with allergen following viral infection on changes in lung function, cellular responses and tight junction expression. Female BALB/c mice were sensitized to ovalbumin and infected with influenza A before receiving a second ovalbumin sensitization and challenge with saline, ovalbumin (OVA) or house dust mite (HDM). Fifteen days post-infection, bronchoalveolar inflammation, serum antibodies, responsiveness to methacholine and barrier integrity were assessed. There was no effect of infection alone on bronchoalveolar lavage cellular inflammation 15 days post-infection; however, OVA or HDM challenge resulted in increased bronchoalveolar inflammation dominated by eosinophils/neutrophils or neutrophils, respectively. Previously infected mice had higher serum OVA-specific IgE compared with uninfected mice. Mice previously infected, sensitized and challenged with OVA were most responsive to methacholine with respect to airway resistance, while HDM challenge caused significant increases in both tissue damping and tissue elastance regardless of previous infection status. Previous influenza infection was associated with decreased claudin-1 expression in all groups and decreased occludin expression in OVA or HDM-challenged mice. This study demonstrates the importance of the respiratory epithelium in pre-sensitized individuals, where influenza-infection-induced barrier disruption resulted in increased systemic OVA sensitization and downstream effects on lung function.
    Keywords house dust mite ; lung function ; BALB/c mice ; influenza ; tight junctions ; epithelial barrier integrity ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 570
    Language English
    Publishing date 2021-08-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Regulation of Cellular Senescence Is Independent from Profibrotic Fibroblast-Deposited ECM

    Kaj E. C. Blokland / Habibie Habibie / Theo Borghuis / Greta J. Teitsma / Michael Schuliga / Barbro N. Melgert / Darryl A. Knight / Corry-Anke Brandsma / Simon D. Pouwels / Janette K. Burgess

    Cells, Vol 10, Iss 1628, p

    2021  Volume 1628

    Abstract: Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. Age is a major risk factor, and both alveolar epithelial cells and lung fibroblasts in this disease exhibit features of cellular senescence, a hallmark of ageing. ... ...

    Abstract Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. Age is a major risk factor, and both alveolar epithelial cells and lung fibroblasts in this disease exhibit features of cellular senescence, a hallmark of ageing. Accumulation of fibrotic extracellular matrix (ECM) is a core feature of IPF and is likely to affect cell function. We hypothesize that aberrant ECM deposition augments fibroblast senescence, creating a perpetuating cycle favouring disease progression. In this study, primary lung fibroblasts were cultured on control and IPF-derived ECM from fibroblasts pretreated with or without profibrotic and prosenescent stimuli, and markers of senescence, fibrosis-associated gene expression and secretion of cytokines were measured. Untreated ECM derived from control or IPF fibroblasts had no effect on the main marker of senescence p16 Ink4a and p21 Waf1/Cip1 . However, the expression of alpha smooth muscle actin (ACTA2) and proteoglycan decorin (DCN) increased in response to IPF-derived ECM. Production of the proinflammatory cytokines C-X-C Motif Chemokine Ligand 8 (CXCL8) by lung fibroblasts was upregulated in response to senescent and profibrotic-derived ECM. Finally, the profibrotic cytokines transforming growth factor β1 (TGF-β1) and connective tissue growth factor (CTGF) were upregulated in response to both senescent- and profibrotic-derived ECM. In summary, ECM deposited by IPF fibroblasts does not induce cellular senescence, while there is upregulation of proinflammatory and profibrotic cytokines and differentiation into a myofibroblast phenotype in response to senescent- and profibrotic-derived ECM, which may contribute to progression of fibrosis in IPF.
    Keywords extracellular matrix ; senescence ; idiopathic pulmonary fibrosis ; proinflammatory ; profibrotic ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2021-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: A Senescence Bystander Effect in Human Lung Fibroblasts

    David W. Waters / Michael Schuliga / Prabuddha S. Pathinayake / Lan Wei / Hui-Ying Tan / Kaj E. C. Blokland / Jade Jaffar / Glen P. Westall / Janette K. Burgess / Cecilia M. Prêle / Steven E. Mutsaers / Christopher L. Grainge / Darryl A. Knight

    Biomedicines, Vol 9, Iss 1162, p

    2021  Volume 1162

    Abstract: Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterised by a dense fibrosing of the lung parenchyma. An association between IPF and cellular senescence is well established and several studies now describe a higher abundance of senescent ... ...

    Abstract Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterised by a dense fibrosing of the lung parenchyma. An association between IPF and cellular senescence is well established and several studies now describe a higher abundance of senescent fibroblasts and epithelial cells in the lungs of IPF patients compared with age-matched controls. The cause of this abnormal accumulation of senescent cells is unknown but evidence suggests that, once established, senescence can be transferred from senescent to non-senescent cells. In this study, we investigated whether senescent human lung fibroblasts (LFs) and alveolar epithelial cells (AECs) could induce a senescent-like phenotype in “naïve” non-senescent LFs in vitro. Primary cultures of LFs from adult control donors (Ctrl-LFs) with a low baseline of senescence were exposed to conditioned medium (CM) from: (i) Ctrl-LFs induced to become senescent using H 2 O 2 or etoposide; (ii) LFs derived from IPF patients (IPF-LFs) with a high baseline of senescence; or (iii) senescence-induced A549 cells, an AEC line. Additionally, ratios of non-senescent Ctrl-LFs and senescence-induced Ctrl-LFs (100:0, 0:100, 50:50, 90:10, 99:1) were co-cultured and their effect on induction of senescence measured. We demonstrated that exposure of naïve non-senescent Ctrl-LFs to CM from senescence-induced Ctrl-LFs and AECs and IPF-LFs increased the markers of senescence including nuclear localisation of phosphorylated-H2A histone family member X (H2AXγ) and expression of p21, IL-6 and IL-8 in Ctrl-LFs. Additionally, co-cultures of non-senescent and senescence-induced Ctrl-LFs induced a senescent-like phenotype in the non-senescent cells. These data suggest that the phenomenon of “senescence-induced senescence” can occur in vitro in primary cultures of human LFs, and provides a possible explanation for the abnormal abundance of senescent cells in the lungs of IPF patients.
    Keywords collagen ; idiopathic pulmonary fibrosis (IPF) ; lung fibroblasts ; senescence ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2021-09-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Reduced SOCS1 Expression in Lung Fibroblasts from Patients with IPF Is Not Mediated by Promoter Methylation or Mir155

    Cecilia M. Prêle / Thomas Iosifidis / Robin J. McAnulty / David R. Pearce / Bahareh Badrian / Tylah Miles / Sarra E. Jamieson / Matthias Ernst / Philip J. Thompson / Geoffrey J. Laurent / Darryl A. Knight / Steven E. Mutsaers

    Biomedicines, Vol 9, Iss 498, p

    2021  Volume 498

    Abstract: The interleukin (IL)-6 family of cytokines and exaggerated signal transducer and activator of transcription (STAT)3 signaling is implicated in idiopathic pulmonary fibrosis (IPF) pathogenesis, but the mechanisms regulating STAT3 expression and function ... ...

    Abstract The interleukin (IL)-6 family of cytokines and exaggerated signal transducer and activator of transcription (STAT)3 signaling is implicated in idiopathic pulmonary fibrosis (IPF) pathogenesis, but the mechanisms regulating STAT3 expression and function are unknown. Suppressor of cytokine signaling (SOCS)1 and SOCS3 block STAT3, and low SOCS1 levels have been reported in IPF fibroblasts and shown to facilitate collagen production. Fibroblasts and lung tissue from IPF patients and controls were used to examine the mechanisms underlying SOCS1 down-regulation in IPF. A significant reduction in basal SOCS1 mRNA in IPF fibroblasts was confirmed. However, there was no difference in the kinetics of activation, and methylation of SOCS1 in control and IPF lung fibroblasts was low and unaffected by 5′-aza-2′-deoxycytidine’ treatment. SOCS1 is a target of microRNA-155 and although microRNA-155 levels were increased in IPF tissue, they were reduced in IPF fibroblasts. Therefore, SOCS1 is not regulated by SOCS1 gene methylation or microRNA155 in these cells. In conclusion, we confirmed that IPF fibroblasts had lower levels of SOCS1 mRNA compared with control fibroblasts, but we were unable to determine the mechanism. Furthermore, although SOCS1 may be important in the fibrotic process, we were unable to find a significant role for SOCS1 in regulating fibroblast function.
    Keywords L-6 ; Jak/STAT pathway ; SOCS1 ; miR155 ; fibroblast ; fibrosis ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: IL-25 blockade augments antiviral immunity during respiratory virus infection

    Teresa C. Williams / Su-Ling Loo / Kristy S. Nichol / Andrew T. Reid / Punnam C. Veerati / Camille Esneau / Peter A. B. Wark / Christopher L. Grainge / Darryl A. Knight / Thomas Vincent / Crystal L. Jackson / Kirby Alton / Richard A. Shimkets / Jason L. Girkin / Nathan W. Bartlett

    Communications Biology, Vol 5, Iss 1, Pp 1-

    2022  Volume 13

    Abstract: IL-25 and its receptor are expressed in airway epithelial cells of healthy individuals and patients with asthma and antibody-mediated blockade of IL-25 enhances antiviral immunity and blocks virus-exacerbated asthma responses. ...

    Abstract IL-25 and its receptor are expressed in airway epithelial cells of healthy individuals and patients with asthma and antibody-mediated blockade of IL-25 enhances antiviral immunity and blocks virus-exacerbated asthma responses.
    Keywords Biology (General) ; QH301-705.5
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Dysregulated Notch Signaling in the Airway Epithelium of Children with Wheeze

    Thomas Iosifidis / Erika N. Sutanto / Samuel T. Montgomery / Patricia Agudelo-Romero / Kevin Looi / Kak-Ming Ling / Nicole C. Shaw / Luke W. Garratt / Jessica Hillas / Kelly M. Martinovich / Elizabeth Kicic-Starcevich / Shyan Vijayasekaran / Francis J. Lannigan / Paul J. Rigby / Darryl A. Knight / Stephen M. Stick / Anthony Kicic

    Journal of Personalized Medicine, Vol 11, Iss 1323, p

    2021  Volume 1323

    Abstract: The airway epithelium of children with wheeze is characterized by defective repair that contributes to disease pathobiology. Dysregulation of developmental processes controlled by Notch has been identified in chronic asthma. However, its role in airway ... ...

    Abstract The airway epithelium of children with wheeze is characterized by defective repair that contributes to disease pathobiology. Dysregulation of developmental processes controlled by Notch has been identified in chronic asthma. However, its role in airway epithelial cells of young children with wheeze, particularly during repair, is yet to be determined. We hypothesized that Notch is dysregulated in primary airway epithelial cells (pAEC) of children with wheeze contributing to defective repair. This study investigated transcriptional and protein expression and function of Notch in pAEC isolated from children with and without wheeze. Primary AEC of children with and without wheeze were found to express all known Notch receptors and ligands, although pAEC from children with wheeze expressed significantly lower NOTCH2 (10-fold, p = 0.004) and higher JAG1 (3.5-fold, p = 0.002) mRNA levels. These dysregulations were maintained in vitro and cultures from children with wheeze displayed altered kinetics of both NOTCH2 and JAG1 expression during repair. Following Notch signaling inhibition, pAEC from children without wheeze failed to repair (wound closure rate of 76.9 ± 3.2%). Overexpression of NOTCH2 in pAEC from children with wheeze failed to rescue epithelial repair following wounding. This study illustrates the involvement of the Notch pathway in airway epithelial wound repair in health and disease, where its dysregulation may contribute to asthma development.
    Keywords pediatrics ; wheeze ; airway epithelium ; wound repair ; Notch ; Medicine ; R
    Subject code 570
    Language English
    Publishing date 2021-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Potential role of stem cells in management of COPD

    Tillie L Hackett / Darryl A Knight / Don D Sin

    International Journal of COPD, Vol 2010, Iss default, Pp 81-

    2010  Volume 88

    Abstract: Tillie L Hackett1,2, Darryl A Knight1,2, Don D Sin1,31UBC James Hogg Research Centre, Heart and Lung Institute, St Paul’s Hospital, Vancouver, BC, Canada, V6Z 1Y6; 2Department of Anesthesiology, Pharmacology and Therapeutics, 3Department of Medicine, ... ...

    Abstract Tillie L Hackett1,2, Darryl A Knight1,2, Don D Sin1,31UBC James Hogg Research Centre, Heart and Lung Institute, St Paul’s Hospital, Vancouver, BC, Canada, V6Z 1Y6; 2Department of Anesthesiology, Pharmacology and Therapeutics, 3Department of Medicine, University of British Columbia, Vancouver, BC CanadaAbstract: Chronic obstructive pulmonary disease (COPD) is a worldwide epidemic affecting over 200 million people and accounting for more than three million deaths annually. The disease is characterized by chronic inflammation of the airways and progressive destruction of lung parenchyma, a process that in most cases is initiated by cigarette smoking. Unfortunately, there are no interventions that have been unequivocally shown to prolong survival in patients with COPD. Regeneration of lung tissue by stem cells from endogenous and exogenous sources is a promising therapeutic strategy. Herein we review the current literature on the characterization of resident stem and progenitor cell niches within the lung, the contribution of mesenchymal stem cells to lung regeneration, and advances in bioengineering of lung tissue.Keywords: COPD, stem cell therapy, epithelial repair, regenerative medicine
    Keywords Diseases of the respiratory system ; RC705-779 ; Specialties of internal medicine ; RC581-951 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Internal medicine ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Subject code 610
    Language English
    Publishing date 2010-03-01T00:00:00Z
    Publisher Dove Press
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Function of the Airway Epithelium in Asthma

    Darryl A. Knight / Prescott G. Woodruff / Teal S. Hallstrand / Stephen T. Holgate

    Journal of Allergy, Vol

    2012  Volume 2012

    Keywords Immunologic diseases. Allergy ; RC581-607 ; Specialties of internal medicine ; RC581-951 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Allergy and Immunology ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2012-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Regulation of xanthine dehydrogensase gene expression and uric acid production in human airway epithelial cells.

    Ryan D Huff / Alan C-Y Hsu / Kristy S Nichol / Bernadette Jones / Darryl A Knight / Peter A B Wark / Philip M Hansbro / Jeremy A Hirota

    PLoS ONE, Vol 12, Iss 9, p e

    2017  Volume 0184260

    Abstract: The airway epithelium is a physical and immunological barrier that protects the pulmonary system from inhaled environmental insults. Uric acid has been detected in the respiratory tract and can function as an antioxidant or damage associated molecular ... ...

    Abstract The airway epithelium is a physical and immunological barrier that protects the pulmonary system from inhaled environmental insults. Uric acid has been detected in the respiratory tract and can function as an antioxidant or damage associated molecular pattern. We have demonstrated that human airway epithelial cells are a source of uric acid. Our hypothesis is that uric acid production by airway epithelial cells is induced by environmental stimuli associated with chronic respiratory diseases. We therefore examined how airway epithelial cells regulate uric acid production.Allergen and cigarette smoke mouse models were performed using house dust mite (HDM) and cigarette smoke exposure, respectively, with outcome measurements of lung uric acid levels. Primary human airway epithelial cells isolated from clinically diagnosed patients with asthma and chronic obstructive pulmonary disease (COPD) were grown in submerged cultures and compared to age-matched healthy controls for uric acid release. HBEC-6KT cells, a human airway epithelial cell line, were grown under submerged monolayer conditions for mechanistic and gene expression studies.HDM, but not cigarette smoke exposure, stimulated uric acid production in vivo and in vitro. Primary human airway epithelial cells from asthma, but not COPD patients, displayed elevated levels of extracellular uric acid in culture. In HBEC-6KT, production of uric acid was sensitive to the xanthine dehydrogenase (XDH) inhibitor, allopurinol, and the ATP Binding Cassette C4 (ABCC4) inhibitor, MK-571. Lastly, the pro-inflammatory cytokine combination of TNF-α and IFN-γ elevated extracellular uric acid levels and XDH gene expression in HBEC-6KT cells.Our results suggest that the active production of uric acid from human airway epithelial cells may be intrinsically altered in asthma and be further induced by pro-inflammatory cytokines.
    Keywords Medicine ; R ; Science ; Q
    Subject code 610
    Language English
    Publishing date 2017-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: Inflammasomes in the lung

    Pinkerton, James W / Avril A.B. Robertson / Darryl A. Knight / Jay C. Horvat / Jeremy A. Hirota / Lisa G. Wood / Luke A.J. O’Neill / Matthew A. Cooper / Philip M. Hansbro / Richard Y. Kim

    Molecular immunology. 2017 June, v. 86

    2017  

    Abstract: Innate immune responses act as first line defences upon exposure to potentially noxious stimuli. The innate immune system has evolved numerous intracellular and extracellular receptors that undertake surveillance for potentially damaging particulates. ... ...

    Abstract Innate immune responses act as first line defences upon exposure to potentially noxious stimuli. The innate immune system has evolved numerous intracellular and extracellular receptors that undertake surveillance for potentially damaging particulates. Inflammasomes are intracellular innate immune multiprotein complexes that form and are activated following interaction with these stimuli. Inflammasome activation leads to the cleavage of pro-IL-1β and release of the pro-inflammatory cytokine, IL-1β, which initiates acute phase pro-inflammatory responses, and other responses are also involved (IL-18, pyroptosis). However, excessive activation of inflammasomes can result in chronic inflammation, which has been implicated in a range of chronic inflammatory diseases. The airways are constantly exposed to a wide variety of stimuli. Inflammasome activation and downstream responses clears these stimuli. However, excessive activation may drive the pathogenesis of chronic respiratory diseases such as severe asthma and chronic obstructive pulmonary disease. Thus, there is currently intense interest in the role of inflammasomes in chronic inflammatory lung diseases and in their potential for therapeutic targeting. Here we review the known associations between inflammasome-mediated responses and the development and exacerbation of chronic lung diseases.
    Keywords asthma ; inflammasomes ; inflammation ; innate immunity ; interleukin-18 ; interleukin-1beta ; lungs ; monitoring ; particulates ; pathogenesis ; receptors ; therapeutics
    Language English
    Dates of publication 2017-06
    Size p. 44-55.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 424427-8
    ISSN 1872-9142 ; 0161-5890
    ISSN (online) 1872-9142
    ISSN 0161-5890
    DOI 10.1016/j.molimm.2017.01.014
    Database NAL-Catalogue (AGRICOLA)

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