Airway Epithelium Dysfunction in Cystic Fibrosis and COPD

Cystic fibrosis is a genetic disease caused by mutations in the CFTR gene, whereas chronic obstructive pulmonary disease (COPD) is mainly caused by environmental factors (mostly cigarette smoking) on a genetically susceptible background. Although the etiology and pathogenesis of these diseases are different, both are associated with progressive airflow obstruction, airway neutrophilic inflammation, and recurrent exacerbations, suggesting common mechanisms. The airway epithelium plays a crucial role in maintaining normal airway functions. Major molecular and morphologic changes occur in the airway epithelium in both CF and COPD, and growing evidence suggests that airway epithelial dysfunction is involved in disease initiation and progression in both diseases. Structural and functional abnormalities in both airway and alveolar epithelium have a relevant impact on alteration of host defences, immune/inflammatory response, and the repair process leading to progressive lung damage and impaired lung function. In this review, we address the evidence for a critical role of dysfunctional airway epithelial cells in chronic airway inflammation and remodelling in CF and COPD, highlighting the common mechanisms involved in the epithelial dysfunction as well as the similarities and differences of the two diseases.

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Somatic cell hemoglobin modulates nitrogen oxide metabolism in the human airway epithelium

Scientific Reports ◽

10.1038/s41598-021-94782-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nadzeya Marozkina ◽

Laura Smith ◽

Yi Zhao ◽

Joe Zein ◽

James F. Chmiel ◽

...

Keyword(s):

Gene Expression ◽

Epithelial Cells ◽

Nitrogen Oxides ◽

Airway Epithelium ◽

Airflow Obstruction ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Human Airway ◽

Human Airway Epithelium ◽

Human Airway Epithelial Cells

AbstractEndothelial hemoglobin (Hb)α regulates endothelial nitric oxide synthase (eNOS) biochemistry. We hypothesized that Hb could also be expressed and biochemically active in the ciliated human airway epithelium. Primary human airway epithelial cells, cultured at air–liquid interface (ALI), were obtained by clinical airway brushings or from explanted lungs. Human airway Hb mRNA data were from publically available databases; or from RT-PCR. Hb proteins were identified by immunoprecipitation, immunoblot, immunohistochemistry, immunofluorescence and liquid chromatography- mass spectrometry. Viral vectors were used to alter Hbβ expression. Heme and nitrogen oxides were measured colorimetrically. Hb mRNA was expressed in human ciliated epithelial cells. Heme proteins (Hbα, β, and δ) were detected in ALI cultures by several methods. Higher levels of airway epithelial Hbβ gene expression were associated with lower FEV1 in asthma. Both Hbβ knockdown and overexpression affected cell morphology. Hbβ and eNOS were apically colocalized. Binding heme with CO decreased extracellular accumulation of nitrogen oxides. Human airway epithelial cells express Hb. Higher levels of Hbβ gene expression were associated with airflow obstruction. Hbβ and eNOS were colocalized in ciliated cells, and heme affected oxidation of the NOS product. Epithelial Hb expression may be relevant to human airways diseases.

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The innate immune function of airway epithelial cells in inflammatory lung disease

European Respiratory Journal ◽

10.1183/09031936.00141514 ◽

2015 ◽

Vol 45 (4) ◽

pp. 1150-1162 ◽

Cited By ~ 141

Author(s):

Pieter S. Hiemstra ◽

Paul B. McCray ◽

Robert Bals

Keyword(s):

Immune Responses ◽

Airway Epithelium ◽

Cell Function ◽

Developmental Regulation ◽

Airway Epithelial Cells ◽

Chronic Obstructive ◽

Airway Epithelial ◽

Tissue Remodelling ◽

Wide Range ◽

Differentiation Pathways

The airway epithelium is now considered to be central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as the first barrier in the defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. Herein, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, chronic obstructive pulmonary fibrosis and cystic fibrosis will be discussed.

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Microbial interaction: Prevotella spp. reduce P.aeruginosa induced inflammation in Cystic Fibrosis bronchial epithelial cells

10.21203/rs.3.rs-40957/v1 ◽

2020 ◽

Author(s):

Anne Bertelsen ◽

Stuart J Elborn ◽

Bettina Schock

Keyword(s):

Cystic Fibrosis ◽

Epithelial Cells ◽

Inflammatory Response ◽

Bacterial Species ◽

Airway Epithelial Cells ◽

Lung Damage ◽

Airway Epithelial ◽

Lung Function Decline ◽

Mapk Signalling ◽

Microbial Environment

Abstract Background: In Cystic Fibrosis (CF) airways, mutations in the Cystic Fibrosis Transmembrane Regulator (CFTR) lead to dehydrated, thick mucus which promotes the establishment of persistent polymicrobial infections and drives chronic airways inflammation. This also predisposes the airways to further infections, a vicious, self-perpetuating cycle causing lung damage and progressive lung function decline. The airways are a poly-microbial environment, containing both aerobic and anaerobic bacterial species. Pseudomonas aeruginosa (P.aeruginosa) infections contribute to the excessive inflammatory response in CF, but the role of anaerobic Prevotella spp., frequently found in CF airways, is not known.Materials: We assessed innate immune signalling in CF airway epithelial cells in response to clinical strains of P.histicola, P.nigresens and P.aeruginosa. CFBE41o- cells were infected with P.aeruginosa (MOI 100, 2h) followed by infection with P.histicola or P.nigrescens (MOI 100, 2h). Cells were incubated under anaerobic conditions for the duration of the experiments.Results: Our study shows that P.histicola and P.nigresens can reduce the growth of P.aeruginosa and dampen the inflammatory response in airway epithelial cells. We specifically illustrate that the presence of Prevotella spp. reduces Toll-like-receptor (TLR)-4, MAPK, NF-kB(p65) signalling and cytokine release (Interleukin (IL)-6, IL-8) in mixed infections. Conclusion: Our work, for the first time, strongly indicates a relationship between P. aeruginosa and anaerobe Prevotella spp. The observed modified NF-kB and MAPK signalling provides some mechanisms of this interaction that could offer a novel therapeutic approach to combat chronic P.aeruginosa infection in people with CF.

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Flagellin From Pseudomonas aeruginosa Modulates SARS-CoV-2 Infectivity in Cystic Fibrosis Airway Epithelial Cells by Increasing TMPRSS2 Expression

Frontiers in Immunology ◽

10.3389/fimmu.2021.714027 ◽

2021 ◽

Vol 12 ◽

Author(s):

Manon Ruffin ◽

Jeanne Bigot ◽

Claire Calmel ◽

Julia Mercier ◽

Maëlle Givelet ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Epithelial Cells ◽

Critical Role ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Health Crisis ◽

Chronic Respiratory Diseases ◽

Cf Transmembrane Conductance Regulator ◽

Main Component

In the coronavirus disease 2019 (COVID-19) health crisis, one major challenge is to identify the susceptibility factors of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in order to adapt the recommendations for populations, as well as to reduce the risk of COVID-19 development in the most vulnerable people, especially patients with chronic respiratory diseases such as cystic fibrosis (CF). Airway epithelial cells (AECs) play a critical role in the modulation of both immune responses and COVID-19 severity. SARS-CoV-2 infects the airway through the receptor angiotensin-converting enzyme 2, and a host protease, transmembrane serine protease 2 (TMPRSS2), plays a major role in SARS-CoV-2 infectivity. Here, we show that Pseudomonas aeruginosa increases TMPRSS2 expression, notably in primary AECs with deficiency of the ion channel CF transmembrane conductance regulator (CFTR). Further, we show that the main component of P. aeruginosa flagella, the protein flagellin, increases TMPRSS2 expression in primary AECs and Calu-3 cells, through activation of Toll-like receptor-5 and p38 MAPK. This increase is particularly seen in Calu-3 cells deficient for CFTR and is associated with an intracellular increased level of SARS-CoV-2 infection, however, with no effect on the amount of virus particles released. Considering the urgency of the COVID-19 health crisis, this result may be of clinical significance for CF patients, who are frequently infected with and colonized by P. aeruginosa during the course of CF and might develop COVID-19.

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Airway epithelial cell isolation techniques affect DNA methylation profiles with consequences for analysis of asthma related perturbations to DNA methylation

Scientific Reports ◽

10.1038/s41598-019-50873-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Rachel L. Clifford ◽

Jamie Patel ◽

Julia L. MacIsaac ◽

Lisa M. McEwen ◽

Simon R. Johnson ◽

...

Keyword(s):

Dna Methylation ◽

Airway Epithelium ◽

Cell Isolation ◽

Airway Epithelial Cells ◽

Contributory Factor ◽

Airway Epithelial ◽

Isolation Technique ◽

Isolation Techniques ◽

Aberrant Dna Methylation ◽

Epithelial Dysfunction

Abstract The airway epithelium forms the interface between the inhaled environment and the lung. The airway epithelium is dysfunctional in asthma and epigenetic mechanisms are considered a contributory factor. We hypothesised that the DNA methylation profiles of cultured primary airway epithelial cells (AECs) would differ between cells isolated from individuals with asthma (n = 17) versus those without asthma (n = 16). AECs were isolated from patients by two different isolation techniques; pronase digestion (9 non-asthmatic, 8 asthmatic) and bronchial brushings (7 non-asthmatic and 9 asthmatic). DNA methylation was assessed using an Illumina Infinium HumanMethylation450 BeadChip array. DNA methylation of AECs clustered by isolation technique and linear regression identified 111 CpG sites differentially methylated between isolation techniques in healthy individuals. As a consequence, the effect of asthmatic status on DNA methylation was assessed within AEC samples isolated using the same technique. In pronase isolated AECs, 15 DNA regions were differentially methylated between asthmatics and non-asthmatics. In bronchial brush isolated AECs, 849 differentially methylated DNA regions were identified with no overlap to pronase regions. In conclusion, regardless of cell isolation technique, differential DNA methylation was associated with asthmatic status in AECs, providing further evidence for aberrant DNA methylation as a signature of epithelial dysfunction in asthma.

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Exocytosis is not involved in activation of Cl− secretion via CFTR in Calu-3 airway epithelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.1998.275.4.c913 ◽

1998 ◽

Vol 275 (4) ◽

pp. C913-C920 ◽

Cited By ~ 42

Author(s):

Johannes Loffing ◽

Bryan D. Moyer ◽

David McCoy ◽

Bruce A. Stanton

Keyword(s):

Cystic Fibrosis ◽

Plasma Membrane ◽

Epithelial Cells ◽

Critical Role ◽

Airway Epithelial Cells ◽

Cell Phenotype ◽

Apical Plasma Membrane ◽

Airway Epithelial ◽

Intracellular Pool ◽

Airway Function

Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) Cl−channel, which mediates transepithelial Cl− transport in a variety of epithelia, including airway, intestine, pancreas, and sweat duct. In some but not all epithelial cells, cAMP stimulates Cl− secretion in part by increasing the number of CFTR Cl− channels in the apical plasma membrane. Because the mechanism whereby cAMP stimulates CFTR Cl− secretion is cell-type specific, our goal was to determine whether cAMP elevates CFTR-mediated Cl− secretion across serous airway epithelial cells by stimulating the insertion of CFTR Cl− channels from an intracellular pool into the apical plasma membrane. To this end we studied Calu-3 cells, a human airway cell line with a serous cell phenotype. Serous cells in human airways, such as Calu-3 cells, express high levels of CFTR, secrete antibiotic-rich fluid, and play a critical role in airway function. Moreover, dysregulation of CFTR-mediated Cl− secretion in serous cells is thought to contribute to the pathophysiology of cystic fibrosis lung disease. We report that cAMP activation of CFTR-mediated Cl− secretion across human serous cells involves stimulation of CFTR channels present in the apical plasma membrane and does not involve the recruitment of CFTR from an intracellular pool to the apical plasma membrane.

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Dysfunctional Inflammation in Cystic Fibrosis Airways: From Mechanisms to Novel Therapeutic Approaches

International Journal of Molecular Sciences ◽

10.3390/ijms22041952 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1952

Author(s):

Alessandra Ghigo ◽

Giulia Prono ◽

Elisa Riccardi ◽

Virginia De Rose

Keyword(s):

Cystic Fibrosis ◽

Critical Role ◽

Airway Epithelial Cells ◽

Lung Damage ◽

Molecular Defect ◽

Apical Surface ◽

Therapeutic Approaches ◽

Beneficial Effects ◽

Anti Inflammatory ◽

Novel Therapeutic

Cystic fibrosis (CF) is an inherited disorder caused by mutations in the gene encoding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, an ATP-gated chloride channel expressed on the apical surface of airway epithelial cells. CFTR absence/dysfunction results in defective ion transport and subsequent airway surface liquid dehydration that severely compromise the airway microenvironment. Noxious agents and pathogens are entrapped inside the abnormally thick mucus layer and establish a highly inflammatory environment, ultimately leading to lung damage. Since chronic airway inflammation plays a crucial role in CF pathophysiology, several studies have investigated the mechanisms responsible for the altered inflammatory/immune response that, in turn, exacerbates the epithelial dysfunction and infection susceptibility in CF patients. In this review, we address the evidence for a critical role of dysfunctional inflammation in lung damage in CF and discuss current therapeutic approaches targeting this condition, as well as potential new treatments that have been developed recently. Traditional therapeutic strategies have shown several limitations and limited clinical benefits. Therefore, many efforts have been made to develop alternative treatments and novel therapeutic approaches, and recent findings have identified new molecules as potential anti-inflammatory agents that may exert beneficial effects in CF patients. Furthermore, the potential anti-inflammatory properties of CFTR modulators, a class of drugs that directly target the molecular defect of CF, also will be critically reviewed. Finally, we also will discuss the possible impact of SARS-CoV-2 infection on CF patients, with a major focus on the consequences that the viral infection could have on the persistent inflammation in these patients.

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Fibroblast growth factor-9 expression in airway epithelial cells amplifies the type I interferon response and alters influenza A virus pathogenesis

10.1101/2021.12.22.473953 ◽

2021 ◽

Author(s):

Bradley Hiller ◽

Yongjun Yin ◽

Yi-Chieh Perng ◽

Ítalo de Araujo Castro ◽

Lindsey Fox ◽

...

Keyword(s):

Epithelial Cells ◽

Virus Infection ◽

Airway Epithelium ◽

Influenza A ◽

Alveolar Epithelium ◽

Airway Epithelial Cells ◽

Type I ◽

Airway Epithelial ◽

Conducting Airway ◽

Respiratory Virus Infection

Influenza A virus (IAV) preferentially infects conducting airway and alveolar epithelial cells in the lung. The outcome of these infections is impacted by the host response, including the production of various cytokines, chemokines, and growth factors. Fibroblast growth factor-9 (FGF9) is required for lung development, can display antiviral activity in vitro, and is upregulated in asymptomatic patients during early IAV infection. We therefore hypothesized that FGF9 would protect the lungs from respiratory virus infection and evaluated IAV pathogenesis in mice that overexpress FGF9 in club cells in the conducting airway epithelium (FGF9-OE mice). However, we found that FGF9-OE mice were highly susceptible to IAV and Sendai virus infection compared to control mice. FGF9-OE mice displayed elevated and persistent viral loads, increased expression of cytokines and chemokines, and increased numbers of infiltrating immune cells as early as 1 day post-infection (dpi). Gene expression analysis showed an elevated type I interferon (IFN) signature in the conducting airway epithelium and analysis of IAV tropism uncovered a dramatic shift in infection from the conducting airway epithelium to the alveolar epithelium in FGF9-OE lungs. These results demonstrate that FGF9 signaling primes the conducting airway epithelium to rapidly induce a localized, protective IFN and proinflammatory cytokine response during viral infection. Although this response protects the airway epithelial cells from IAV infection, it allows for early and enhanced infection of the alveolar epithelium, ultimately leading to increased morbidity and mortality. Our study illuminates a novel role for FGF9 in regulating respiratory virus infection and pathogenesis.

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Airway epithelial-targeted nanoparticles for asthma therapy

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00237.2019 ◽

2020 ◽

Vol 318 (3) ◽

pp. L500-L509 ◽

Cited By ~ 2

Author(s):

Stanislav Kan ◽

Dewi Melani Hariyadi ◽

Christopher Grainge ◽

Darryl A. Knight ◽

Nathan W. Bartlett ◽

...

Keyword(s):

Drug Delivery ◽

Epithelial Cells ◽

Airway Epithelium ◽

Airflow Obstruction ◽

Airway Epithelial Cells ◽

Therapeutic Interventions ◽

Asthma Therapy ◽

Airway Epithelial ◽

Management Options ◽

Number Of Patients

Asthma is a common chronic inflammatory disease associated with intermittent airflow obstruction caused by airway inflammation, mucus overproduction, and bronchial hyperresponsiveness. Despite current treatment and management options, a large number of patients with asthma still have poorly controlled disease and are susceptible to acute exacerbations, usually caused by a respiratory virus infection. As a result, there remains a need for novel therapies to achieve better control and prevent/treat exacerbations. Nanoparticles (NPs), including extracellular vesicles (EV) and their synthetic counterparts, have been developed for drug delivery in respiratory diseases. In the case of asthma, where airway epithelium dysfunction, including dysregulated differentiation of epithelial cells, impaired barrier, and immune response, is a driver of disease, targeting airway epithelial cells with NPs may offer opportunities to repair or reverse these dysfunctions with therapeutic interventions. EVs possess multiple advantages for airway epithelial targeting, such as their natural intrinsic cell-targeting properties and low immunogenicity. Synthetic NPs can be coated with muco-inert polymers to overcome biological barriers such as mucus and the phagocytic response of immune cells. Targeting ligands could be also added to enhance targeting specificity to epithelial cells. The review presents current understanding and advances in NP-mediated drug delivery to airway epithelium for asthma therapy. Future perspectives in this therapeutic strategy will also be discussed, including the development of novel formulations and physiologically relevant preclinical models.

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Airway Epithelial Dysfunction in Asthma: Relevant to Epidermal Growth Factor Receptors and Airway Epithelial Cells

Journal of Clinical Medicine ◽

10.3390/jcm9113698 ◽

2020 ◽

Vol 9 (11) ◽

pp. 3698

Author(s):

Hideki Inoue ◽

Kaho Akimoto ◽

Tetsuya Homma ◽

Akihiko Tanaka ◽

Hironori Sagara

Keyword(s):

Growth Factor ◽

Airway Epithelium ◽

Airway Remodeling ◽

Airway Epithelial Cells ◽

Epidermal Growth Factor Receptors ◽

Airway Epithelial ◽

Asthmatic Airway ◽

Epidermal Growth ◽

Egfr Family ◽

Epithelial Dysfunction

Airway epithelium plays an important role as the first barrier from external pathogens, including bacteria, viruses, chemical substances, and allergic components. Airway epithelial cells also have pivotal roles as immunological coordinators of defense mechanisms to transfer signals to immunologic cells to eliminate external pathogens from airways. Impaired airway epithelium allows the pathogens to remain in the airway epithelium, which induces aberrant immunological reactions. Dysregulated functions of asthmatic airway epithelium have been reported in terms of impaired wound repair, fragile tight junctions, and excessive proliferation, leading to airway remodeling, which contributes to aberrant airway responses caused by external pathogens. To maintain airway epithelium integrity, a family of epidermal growth factor receptors (EGFR) have pivotal roles in mechanisms of cell growth, proliferation, and differentiation. There are extensive studies focusing on the relation between EGFR and asthma pathophysiology, which describe airway remodeling, airway hypermucus secretion, as well as immunological responses of airway inflammation. Furthermore, the second EGFR family member, erythroblastosis oncogene B2 (ErbB2), has been recognized to be involved with impaired wound recovery and epithelial differentiation in asthmatic airway epithelium. In this review, the roles of the EGFR family in asthmatic airway epithelium are focused on to elucidate the pathogenesis of airway epithelial dysfunction in asthma.

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