1
|
Bidirectional interaction of airway epithelial remodeling and inflammation in asthma. Clin Sci (Lond) 2020; 134:1063-1079. [PMID: 32369100 DOI: 10.1042/cs20191309] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/28/2020] [Accepted: 04/20/2020] [Indexed: 12/18/2022]
Abstract
Asthma is a chronic disease of the airways that has long been viewed predominately as an inflammatory condition. Accordingly, current therapeutic interventions focus primarily on resolving inflammation. However, the mainstay of asthma therapy neither fully improves lung function nor prevents disease exacerbations, suggesting involvement of other factors. An emerging concept now holds that airway remodeling, another major pathological feature of asthma, is as important as inflammation in asthma pathogenesis. Structural changes associated with asthma include disrupted epithelial integrity, subepithelial fibrosis, goblet cell hyperplasia/metaplasia, smooth muscle hypertrophy/hyperplasia, and enhanced vascularity. These alterations are hypothesized to contribute to airway hyperresponsiveness, airway obstruction, airflow limitation, and progressive decline of lung function in asthmatic individuals. Consequently, targeting inflammation alone does not suffice to provide optimal clinical benefits. Here we review asthmatic airway remodeling, focusing on airway epithelium, which is critical to maintaining a healthy respiratory system, and is the primary defense against inhaled irritants. In asthma, airway epithelium is both a mediator and target of inflammation, manifesting remodeling and resulting obstruction among its downstream effects. We also highlight the potential benefits of therapeutically targeting airway structural alterations. Since pathological tissue remodeling is likewise observed in other injury- and inflammation-prone tissues and organs, our discussion may have implications beyond asthma and lung disease.
Collapse
|
2
|
What Have In Vitro Co-Culture Models Taught Us about the Contribution of Epithelial-Mesenchymal Interactions to Airway Inflammation and Remodeling in Asthma? Cells 2020; 9:cells9071694. [PMID: 32679790 PMCID: PMC7408556 DOI: 10.3390/cells9071694] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 12/14/2022] Open
Abstract
As the lung develops, epithelial-mesenchymal crosstalk is essential for the developmental processes that drive cell proliferation, differentiation, and extracellular matrix (ECM) production within the lung epithelial-mesenchymal trophic unit (EMTU). In asthma, a number of the lung EMTU developmental signals have been associated with airway inflammation and remodeling, which has led to the hypothesis that aberrant activation of the asthmatic EMTU may lead to disease pathogenesis. Monoculture studies have aided in the understanding of the altered phenotype of airway epithelial and mesenchymal cells and their contribution to the pathogenesis of asthma. However, 3-dimensional (3D) co-culture models are needed to enable the study of epithelial-mesenchymal crosstalk in the setting of the in vivo environment. In this review, we summarize studies using 3D co-culture models to assess how defective epithelial-mesenchymal communication contributes to chronic airway inflammation and remodeling within the asthmatic EMTU.
Collapse
|
3
|
Castro-Rodriguez JA, Saglani S, Rodriguez-Martinez CE, Oyarzun MA, Fleming L, Bush A. The relationship between inflammation and remodeling in childhood asthma: A systematic review. Pediatr Pulmonol 2018; 53:824-835. [PMID: 29469196 DOI: 10.1002/ppul.23968] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/25/2018] [Indexed: 12/30/2022]
Abstract
OBJECTIVES We aimed to perform a systematic review of all studies with direct measurements of both airway inflammation and remodeling in the subgroup of children with repeated wheezing and/or persistent asthma severe enough to warrant bronchoscopy, to address whether airway inflammation precedes remodeling or is a parallel process, and also to assess the impact of remodeling on lung function. METHODS Four databases were searched up to June 2017. Two independent reviewers screened the literature and extracted relevant data. RESULTS We found 526 references, and 39 studies (2390 children under 18 years old) were included. Airway inflammation (eosinophilic/neutrophilic) and remodeling were not present in wheezers at a mean age of 12 months, but in older pre-school children (mean 2.5 years), remodeling (mainly increased reticular basement membrane [RBM] thickness and increased area of airway smooth muscle) and also airway eosinophilia was reported. This was worse in school-age children. RBM thickness was similar in atopic and non-atopic preschool wheezers. Airway remodeling was correlated with lung function in seven studies, with FeNO in three, and with HRCT-scan in one. Eosinophilic inflammation was not seen in patients without remodeling. There were no invasive longitudinal or intervention studies. CONCLUSION The relationship between inflammation and remodeling in children cannot be determined. Failure to demonstrate eosinophilic inflammation in the absence of remodeling is contrary to the hypothesis that inflammation causes these changes. We need reliable, non-invasive markers of remodeling in particular if this is to be addressed.
Collapse
Affiliation(s)
- Jose A Castro-Rodriguez
- Division of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sejal Saglani
- National Heart and Lung Institute, Imperial College London, London, UK.,Respiratory Paediatrics, Royal Brompton Hospital, London, UK
| | - Carlos E Rodriguez-Martinez
- Department of Pediatrics, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia.,Department of Pediatric Pulmonology and Pediatric Critical Care Medicine, School of Medicine, Universidad El Bosque, Bogotá, Colombia
| | - Maria A Oyarzun
- Division of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Louis Fleming
- National Heart and Lung Institute, Imperial College London, London, UK.,Respiratory Paediatrics, Royal Brompton Hospital, London, UK
| | - Andrew Bush
- National Heart and Lung Institute, Imperial College London, London, UK.,Respiratory Paediatrics, Royal Brompton Hospital, London, UK
| |
Collapse
|
4
|
Royce SG, Rele S, Broughton BRS, Kelly K, Samuel CS. Intranasal administration of mesenchymoangioblast-derived mesenchymal stem cells abrogates airway fibrosis and airway hyperresponsiveness associated with chronic allergic airways disease. FASEB J 2017. [PMID: 28626025 DOI: 10.1096/fj.201700178r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Structural changes known as airway remodeling (AWR) characterize chronic/severe asthma and contribute to lung dysfunction. Thus, we assessed the in vivo efficacy of induced pluripotent stem cell and mesenchymoangioblast-derived mesenchymal stem cells (MCA-MSCs) on AWR in a murine model of chronic allergic airways disease (AAD)/asthma. Female Balb/c mice were subjected to a 9-wk model of ovalbumin (Ova)-induced chronic AAD and treated intravenously or intranasally with MCA-MSCs from weeks 9 to 11. Changes in airway inflammation (AI), AWR, and airway hyperresponsiveness (AHR) were assessed. Ova-injured mice presented with AI, goblet cell metaplasia, epithelial thickening, increased airway TGF-β1 levels, subepithelial myofibroblast and collagen accumulation, total lung collagen concentration, and AHR (all P < 0.001 vs. uninjured control group). Apart from epithelial thickness, all other parameters measured were significantly, although not totally, decreased by intravenous delivery of MCA-MSCs to Ova-injured mice. In comparison, intranasal delivery of MCA-MSCs to Ova-injured mice significantly decreased all parameters measured (all P < 0.05 vs. Ova group) and, most notably, normalized aberrant airway TGF-β1 levels, airway/lung fibrosis, and AHR to values measured in uninjured animals. MCA-MSCs also increased collagen-degrading gelatinase levels. Hence, direct delivery of MCA-MSCs offers great therapeutic benefit for the AWR and AHR associated with chronic AAD.-Royce, S. G., Rele, S., Broughton, B. R. S., Kelly, K., Samuel, C. S. Intranasal administration of mesenchymoangioblast-derived mesenchymal stem cells abrogates airway fibrosis and airway hyperresponsiveness associated with chronic allergic airways disease.
Collapse
Affiliation(s)
- Simon G Royce
- Fibrosis Laboratory, Monash University, Clayton, Victoria, Australia; .,Department of Medicine, Central Clinical School, Monash University, Prahran, Victoria, Australia; and
| | - Siddharth Rele
- Fibrosis Laboratory, Monash University, Clayton, Victoria, Australia
| | - Brad R S Broughton
- Cardiovascular and Pulmonary Pharmacology Group, Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Kilian Kelly
- Cynata Therapeutics, Armadale, Victoria, Australia
| | - Chrishan S Samuel
- Fibrosis Laboratory, Monash University, Clayton, Victoria, Australia;
| |
Collapse
|
5
|
Ling KM, Sutanto EN, Iosifidis T, Kicic-Starcevich E, Looi K, Garratt LW, Martinovich KM, Lannigan FJ, Knight DA, Stick SM, Kicic A. Reduced transforming growth factor β1 (TGF-β1) in the repair of airway epithelial cells of children with asthma. Respirology 2016; 21:1219-26. [PMID: 27221564 DOI: 10.1111/resp.12810] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 02/24/2016] [Accepted: 03/10/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Evidence into the role of TGF-β1 in airway epithelial repair in asthma is still controversial. This study tested the hypothesis that the reduced TGF-β1 levels previously observed in paediatric asthmatic airway epithelial cells directly contribute to the dysregulated repair seen in these cells. METHODS Primary airway epithelial cells (pAEC) from children with asthma (n = 16) and non-asthmatic subjects (n = 20) were isolated, and subcultured for investigation of TGF-β1 gene and protein via quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Expression of other associated genes such as integrins αvβ6, αvβ8 and MT1-MMP were also tested. Small interfering RNA (siRNA) was employed to assess the role of TGF-β1 during wound repair. RESULTS TGF-β1 gene and protein expression were significantly downregulated in asthmatic pAEC over the course of repair, compared with cells from non-asthmatic children. Messenger RNA (mRNA) expression of TGF-β1 was also directly implicated in non-asthmatic and asthmatic pAEC proliferation over their quiescent counterparts. Small interfering RNA-mediated knockdown of TGF-β1 compromised repair in non-asthmatic pAEC and exacerbated the dysregulated repair seen in asthmatic pAEC. Expression of major TGF-β1 activators of epithelial cells, integrin αvβ6 and αvβ8 was also measured and there was no difference in αvβ6 gene expression between the two cohorts. Although integrin αvβ8 gene expression was significantly higher in asthmatic pAEC, the expression of MT1-MMP (MMP14) which facilitates the αvβ8 mediated TGF-β1 activation was significantly downregulated. CONCLUSION Our data has highlighted the importance of TGF-β1 in pAEC wound repair in vitro. The significantly lower levels seen in asthmatic pAEC subsequently contributes to the dysregulated repair observed in these cells.
Collapse
Affiliation(s)
- Kak-Ming Ling
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Erika N Sutanto
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia.,Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia
| | - Thomas Iosifidis
- School of Paediatrics and Child Health, The University of Western Australia, Nedlands, Western Australia, Australia.,Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia and Harry Perkins Institute, Nedlands, Western Australia, Australia
| | - Elizabeth Kicic-Starcevich
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia.,Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia
| | - Kevin Looi
- School of Paediatrics and Child Health, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Luke W Garratt
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia.,School of Paediatrics and Child Health, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Kelly M Martinovich
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Francis J Lannigan
- School of Medicine, Notre Dame University, Fremantle, Western Australia, Australia
| | - Darryl A Knight
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia.,Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephen M Stick
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia.,Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.,School of Paediatrics and Child Health, The University of Western Australia, Nedlands, Western Australia, Australia.,Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia and Harry Perkins Institute, Nedlands, Western Australia, Australia
| | - Anthony Kicic
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, Western Australia, Australia. .,Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia. .,School of Paediatrics and Child Health, The University of Western Australia, Nedlands, Western Australia, Australia. .,Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia and Harry Perkins Institute, Nedlands, Western Australia, Australia.
| |
Collapse
|
6
|
Ge Q, Zeng Q, Tjin G, Lau E, Black JL, Oliver BGG, Burgess JK. Differential deposition of fibronectin by asthmatic bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1093-102. [DOI: 10.1152/ajplung.00019.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 09/01/2015] [Indexed: 11/22/2022] Open
Abstract
Altered ECM protein deposition is a feature in asthmatic airways. Fibronectin (Fn), an ECM protein produced by human bronchial epithelial cells (HBECs), is increased in asthmatic airways. This study investigated the regulation of Fn production in asthmatic or nonasthmatic HBECs and whether Fn modulated HBEC proliferation and inflammatory mediator secretion. The signaling pathways underlying transforming growth factor (TGF)-β1-regulated Fn production were examined using specific inhibitors for ERK, JNK, p38 MAPK, phosphatidylinositol 3 kinase, and activin-like kinase 5 (ALK5). Asthmatic HBECs deposited higher levels of Fn in the ECM than nonasthmatic cells under basal conditions, whereas cells from the two groups had similar levels of Fn mRNA and soluble Fn. TGF-β1 increased mRNA levels and ECM and soluble forms of Fn but decreased cell proliferation in both cells. The rate of increase in Fn mRNA was higher in nonasthmatic cells. However, the excessive amounts of ECM Fn deposited by asthmatic cells after TGF-β1 stimulation persisted compared with nonasthmatic cells. Inhibition of ALK5 completely prevented TGF-β1-induced Fn deposition. Importantly, ECM Fn increased HBEC proliferation and IL-6 release, decreased PGE2 secretion, but had no effect on VEGF release. Soluble Fn had no effect on cell proliferation and inflammatory mediator release. Asthmatic HBECs are intrinsically primed to produce more ECM Fn, which when deposited into the ECM, is capable of driving remodeling and inflammation. The increased airway Fn may be one of the key driving factors in the persistence of asthma and represents a novel, therapeutic target.
Collapse
Affiliation(s)
- Qi Ge
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
- Discipline of Pharmacology, Sydney Medical School, The University of Sydney, New South Wales, Australia; and
| | - Qingxiang Zeng
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
| | - Gavin Tjin
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
| | - Edmund Lau
- Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Judith L. Black
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
- Discipline of Pharmacology, Sydney Medical School, The University of Sydney, New South Wales, Australia; and
| | - Brian G. G. Oliver
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
- Discipline of Pharmacology, Sydney Medical School, The University of Sydney, New South Wales, Australia; and
| | - Janette K. Burgess
- Respiratory Cellular and Molecular Biology Group, Woolcock Institute of Medical Research, Sydney, New South Wales, Australia
- Discipline of Pharmacology, Sydney Medical School, The University of Sydney, New South Wales, Australia; and
| |
Collapse
|
7
|
Furuya Y, Furuya AKM, Roberts S, Sanfilippo AM, Salmon SL, Metzger DW. Prevention of Influenza Virus-Induced Immunopathology by TGF-β Produced during Allergic Asthma. PLoS Pathog 2015; 11:e1005180. [PMID: 26407325 PMCID: PMC4583434 DOI: 10.1371/journal.ppat.1005180] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 09/01/2015] [Indexed: 12/14/2022] Open
Abstract
Asthma is believed to be a risk factor for influenza infection, however little experimental evidence exists to directly demonstrate the impact of asthma on susceptibility to influenza infection. Using a mouse model, we now report that asthmatic mice are actually significantly more resistant to a lethal influenza virus challenge. Notably, the observed increased resistance was not attributable to enhanced viral clearance, but instead, was due to reduced lung inflammation. Asthmatic mice exhibited a significantly reduced cytokine storm, as well as reduced total protein levels and cytotoxicity in the airways, indicators of decreased tissue injury. Further, asthmatic mice had significantly increased levels of TGF-β1 and the heightened resistance of asthmatic mice was abrogated in the absence of TGF-β receptor II. We conclude that a transient increase in TGF-β expression following acute asthma can induce protection against influenza-induced immunopathology. Influenza and asthma represent the two major lung diseases in humans. While most studies have focused on exacerbation of asthma symptoms by influenza virus infection, the effects of asthma on susceptibility to influenza virus infections has been far less studied. Using a novel mouse model of asthma and influenza infection, we show that asthmatic mice are highly resistant to primary challenge with the 2009 influenza pandemic strain (CA04) compared to non-asthmatic mice. The increased resistance of asthmatic mice is not due to the enhanced T or B cell immunity but rather, to a strong anti-inflammatory TGF-beta response triggered by asthma. This study is the first to provide a mechanistic explanation for asthma-mediated protection during the 2009 influenza pandemic.
Collapse
Affiliation(s)
- Yoichi Furuya
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Andrea K. M. Furuya
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Sean Roberts
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Alan M. Sanfilippo
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Sharon L. Salmon
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Dennis W. Metzger
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
- * E-mail:
| |
Collapse
|
8
|
Woodman LB, Wan WYH, Milone R, Grace K, Sousa A, Williamson R, Brightling CE. Synthetic response of stimulated respiratory epithelium: modulation by prednisolone and iKK2 inhibition. Chest 2013; 143:1656-1666. [PMID: 23238614 PMCID: PMC3673662 DOI: 10.1378/chest.12-1187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: The airway epithelium plays a central role in wound repair and host defense
and is implicated in the immunopathogenesis of asthma. Whether there are
intrinsic differences between the synthetic capacity of epithelial cells
derived from subjects with asthma and healthy control subjects and how this
mediator release is modulated by antiinflammatory therapy remains uncertain.
We sought to examine the synthetic function of epithelial cells from
different locations in the airway tree from subjects with and without asthma
and to determine the effects of antiinflammatory therapies upon this
synthetic capacity. Methods: Primary epithelial cells were derived from 17 subjects with asthma and 16
control subjects. The release of 13 cytokines and chemokines from nasal,
bronchial basal, and air-liquid interface differentiated epithelial cells
before and after stimulation with IL-1β, IL-1β and
interferon-γ, or Poly-IC (Toll-like receptor 3 agonist) was measured
using MesoScale discovery or enzyme-linked immunosorbent assay, and the
effects of prednisolone and an inhibitor of nuclear factor κ-B2
(IKK2i) were determined. Results: The pattern of release of cytokines and chemokines was significantly
different between nasal, bronchial basal, and differentiated epithelial
cells but not between health and disease. Stimulation of the epithelial
cells caused marked upregulation of most mediators, which were broadly
corticosteroid unresponsive but attenuated by IKK2i. Conclusion: Synthetic capacity of primary airway epithelial cells varied between location
and degree of differentiation but was not disease specific. Activation of
epithelial cells by proinflammatory cytokines and toll-like receptor 3
agonism is attenuated by IKK2i, but not corticosteroids, suggesting that
IKK2i may represent an important novel therapy for asthma.
Collapse
Affiliation(s)
- Lucy Bianca Woodman
- Institute for Lung Health, Department of Infection, Immunity and Inflammation, University of Leicester and Department of Respiratory Medicine, Glenfield Hospital, Leicester, England
| | - Wing Yan Heidi Wan
- Institute for Lung Health, Department of Infection, Immunity and Inflammation, University of Leicester and Department of Respiratory Medicine, Glenfield Hospital, Leicester, England
| | - Roberta Milone
- GlaxoSmithKline, Refractory Respiratory Inflammation DPU, Respiratory CEDD Biomarker Discovery Group, Stevenage, England
| | - Ken Grace
- GlaxoSmithKline, Refractory Respiratory Inflammation DPU, Respiratory CEDD Biomarker Discovery Group, Stevenage, England
| | - Ana Sousa
- GlaxoSmithKline, Refractory Respiratory Inflammation DPU, Respiratory CEDD Biomarker Discovery Group, Stevenage, England
| | - Rick Williamson
- GlaxoSmithKline, Refractory Respiratory Inflammation DPU, Respiratory CEDD Biomarker Discovery Group, Stevenage, England
| | - Christopher Edward Brightling
- Institute for Lung Health, Department of Infection, Immunity and Inflammation, University of Leicester and Department of Respiratory Medicine, Glenfield Hospital, Leicester, England.
| |
Collapse
|
9
|
|
10
|
Pelaia G, Vatrella A, Maselli R. The potential of biologics for the treatment of asthma. Nat Rev Drug Discov 2012. [DOI: 10.1038/nrd3792] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
11
|
Shifren A, Witt C, Christie C, Castro M. Mechanisms of remodeling in asthmatic airways. J Allergy (Cairo) 2012; 2012:316049. [PMID: 22315625 PMCID: PMC3270414 DOI: 10.1155/2012/316049] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 09/07/2011] [Accepted: 10/10/2011] [Indexed: 01/09/2023] Open
Abstract
Asthma is a chronic inflammatory airway disorder characterized by airway hyperresponsiveness and reversible airflow obstruction. Subgroups of asthma patients develop airflow obstruction that is irreversible or only partially reversible and experience an accelerated rate of lung function decline. The structural changes in the airways of these patients are referred to as airway remodeling. All elements of the airway wall are involved, and remodeled airway wall thickness is substantially increased compared to normal control airways. Airway remodeling is thought to contribute to the subphenotypes of irreversible airflow obstruction and airway hyperresponsiveness, and it has been associated with increased disease severity. Reversal of remodeling is therefore of paramount therapeutic importance, and mechanisms responsible for airway remodeling are feasible therapeutic targets for asthma treatment. This paper will focus on our current understanding of the mechanisms of airway remodeling in asthma and potential targets for future intervention.
Collapse
Affiliation(s)
- Adrian Shifren
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chad Witt
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chandrika Christie
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Mario Castro
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
12
|
Kicic A, Hallstrand TS, Sutanto EN, Stevens PT, Kobor MS, Taplin C, Paré PD, Beyer RP, Stick SM, Knight DA. Decreased fibronectin production significantly contributes to dysregulated repair of asthmatic epithelium. Am J Respir Crit Care Med 2010; 181:889-98. [PMID: 20110557 DOI: 10.1164/rccm.200907-1071oc] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
RATIONALE Damage to airway epithelium is followed by deposition of extracellular matrix (ECM) and migration of adjacent epithelial cells. We have shown that epithelial cells from children with asthma fail to heal a wound in vitro. OBJECTIVES To determine whether dysregulated ECM production by the epithelium plays a role in aberrant repair in asthma. METHODS Airway epithelial cells (AEC) from children with asthma (n = 36), healthy atopic control subjects (n = 23), and healthy nonatopic control subjects (n = 53) were investigated by microarray, gene expression and silencing, transcript regulation analysis, and ability to close mechanical wounds. MEASUREMENTS AND MAIN RESULTS Time to repair a mechanical wound in vitro by AEC from healthy and atopic children was not significantly different and both were faster than AEC from children with asthma. Microarray analysis revealed differential expression of multiple gene sets associated with repair and remodeling in asthmatic AEC. Fibronectin (FN) was the only ECM component whose expression was significantly lower in asthmatic AEC. Expression differences were verified by quantitative polymerase chain reaction and ELISA, and reduced FN expression persisted in asthmatic cells over passage. Silencing of FN expression in nonasthmatic AEC inhibited wound repair, whereas addition of FN to asthmatic AEC restored reparative capacity. Asthmatic AEC failed to synthesize FN in response to wounding or cytokine/growth factor stimulation. Exposure to 5', 2'deoxyazacytidine had no effect on FN expression and subsequent analysis of the FN promoter did not show evidence of DNA methylation. CONCLUSIONS These data show that the reduced capacity of asthmatic epithelial cells to secrete FN is an important contributor to the dysregulated AEC repair observed in these cells.
Collapse
Affiliation(s)
- Anthony Kicic
- Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, 6001, Western Australia, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
KUROISHI S, SUDA T, FUJISAWA T, IDE K, INUI N, NAKAMURA Y, NAKAMURA H, CHIDA K. Epithelial-mesenchymal transition induced by transforming growth factor-β1 in mouse tracheal epithelial cells. Respirology 2009; 14:828-37. [DOI: 10.1111/j.1440-1843.2009.01561.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
14
|
Altraja S, Jaama J, Valk E, Altraja A. Changes in the proteome of human bronchial epithelial cells following stimulation with leucotriene E4 and transforming growth factor-beta1. Respirology 2009; 14:39-45. [PMID: 19144047 DOI: 10.1111/j.1440-1843.2008.01414.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Activated bronchial epithelial cells exert considerable potential to maintain a microenvironment in the airway wall that promotes airway inflammation and remodelling. Cysteinyl leucotrienes (CysLT) and transforming growth factor-beta(1) (TGF-beta(1)) are both increased in asthmatic airways and may influence the pathophysiology of disease. However, the consequences of activation of bronchial epithelial cells by these mediators are not fully understood. A proteomic-based approach was used to characterize the inflammatory pathways in bronchial epithelial cells after stimulation with CysLT and TGF-beta(1). METHODS Human bronchial epithelial cells (BEAS-2B) were stimulated with 1 ng/mL TGF-beta(1) and 50 nmol/L leucotriene E(4) (LTE(4)) for 48 h and whole-cell lysates were subjected to two-dimensional gel electrophoresis. Proteins showing statistically significant differential expression were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database searching. RESULTS Stimulation with LTE(4) increased the expression of three proteins and five proteins showed decreased expression. Of the latter group, two were definitively identified as heat shock protein (Hsp90 alpha) and stress-70 protein. Hsp90 alpha forms a heterocomplex with the glucocorticoid receptor (GR) and a significant decrease in GR following LTE(4) stimulation was confirmed. TGF-beta(1) downregulated 18 intracellular proteins, including lamin A/C, glyceraldehyde-3-phosphate dehydrogenase, protein DJ-1, voltage-dependent calcium channel gamma-7 subunit, heterogeneous nuclear ribonucleoprotein A2/B1 and stress-70 protein. CONCLUSIONS The current findings suggest that by downregulating GR and Hsp90 alpha, CysLT may interfere with the action of glucocorticoids. Overall, the results confirm the complex role of bronchial epithelium in aspects of airway inflammation and remodelling.
Collapse
Affiliation(s)
- Siiri Altraja
- Department of Pulmonary Medicine, Institute of General and Molecular Pathology, University of Tartu, Tartu, Estonia.
| | | | | | | |
Collapse
|
15
|
Murphy DM, Forrest IA, Corris PA, Johnson GE, Small T, Jones D, Fisher AJ, Egan JJ, Cawston TE, Ward C, Lordan JL. Simvastatin attenuates release of neutrophilic and remodeling factors from primary bronchial epithelial cells derived from stable lung transplant recipients. Am J Physiol Lung Cell Mol Physiol 2008; 294:L592-9. [DOI: 10.1152/ajplung.00386.2007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Obliterative bronchiolitis (OB), the major cause of chronic lung allograft dysfunction, is characterized by airway neutrophilia, inflammation, and remodeling, with progressive fibroproliferation and obliteration of small airways that ultimately leads to patient death. Statins have potential anti-inflammatory effects and have been demonstrated to confer a survival advantage in lung transplant patients. We postulated that the beneficial effects of simvastatin in lung transplantation are in part due to inhibition of the epithelial production of key mediators of neutrophil chemotaxis, inflammation, and airway remodeling. Our objective was to assess the effect of simvastatin on a unique population of primary bronchial epithelial cells (PBECs) derived from stable lung allografts, with specific reference to airway neutrophilia and remodeling. PBEC cultures were stimulated with IL-17 or transforming growth factor (TGF)-β, with and without simvastatin. Supernatant levels of factors critical to driving airway neutrophilia and remodeling were measured. IL-17 upregulated IL-8, IL-6, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), and VEGF, whereas TGF-β increased IL-6, GM-CSF, matrix metalloproteinase (MMP)-2, and MMP-9. Simvastatin attenuated effects of both IL-17 and TGF-β. We have demonstrated the ability of simvastatin to attenuate release of airway neutrophilic and remodeling mediators and to inhibit their upregulation by TGF-β and IL-17. These data illustrate the potential of simvastatin to alleviate neutrophilic airway inflammation and remodeling in the transplanted lung and may have additional relevance to other neutrophilic airway conditions, such as chronic obstructive pulmonary disease.
Collapse
|
16
|
Bossé Y, Thompson C, McMahon S, Dubois CM, Stankova J, Rola-Pleszczynski M. Leukotriene D4-induced, epithelial cell-derived transforming growth factor beta1 in human bronchial smooth muscle cell proliferation. Clin Exp Allergy 2007; 38:113-21. [PMID: 18028462 DOI: 10.1111/j.1365-2222.2007.02873.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Cysteinyl-leukotrienes (cys-LTs) orchestrate many pathognomonic features of asthma in animal models of allergic airway inflammation, including bronchial smooth muscle cell (BSMC) hyperplasia. However, because cys-LTs alone do not induce mitogenesis in monocultures of human BSMC, the effect observed in vivo seemingly involves indirect mechanisms, which are still undefined. OBJECTIVE This study aims to investigate the regulatory role of leukotriene (LT)D(4) on TGF-beta1 expression in airway epithelial cells and the consequence of this interplay on BSMC proliferation. METHODS HEK293 cells stably transfected with cys-LT receptor 1 (CysLT1) (293LT1) were stimulated with LTD(4) and TGF-beta1 mRNA and protein expression was measured using Northern blot and ELISA, respectively. Conditioned medium (CM) harvested from LTD(4)-treated cells was then assayed for its proliferative effect on primary human BSMC. TGF-beta1 mRNA expression was also determined in tumoural type II pneumocytes A549 and in normal human bronchial epithelial cells (NHBE) following LTD(4) stimulation. RESULTS The results demonstrated that LTD(4)-induced TGF-beta1 mRNA production in a time- and concentration-dependent manner in 293LT1. TGF-beta1 secretion was also up-regulated and CM from LTD(4)-treated 293LT1 was shown to increase BSMC proliferation in a TGF-beta1-dependent manner. The increased expression of TGF-beta1 mRNA by LTD(4) also occured in A549 and NHBE cells via a CysLT1-dependent mechanism. CONCLUSION In conclusion, elevated expression of cys-LTs in asthmatic airways might contribute to BSMC hyperplasia and concomitant clinical features of asthma such as airway hyperresponsiveness via a paracrine loop involving TGF-beta1 production by airway epithelial cells.
Collapse
Affiliation(s)
- Y Bossé
- Department of Pediatrics, Immunology Division, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | | | | | | | | | | |
Collapse
|
17
|
Julius P, Lommatzsch M, Kuepper M, Bratke K, Faehndrich S, Luttmann W, Virchow JC. Safety of segmental allergen challenge in human allergic asthma. J Allergy Clin Immunol 2007; 121:712-7. [PMID: 18028992 DOI: 10.1016/j.jaci.2007.08.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 07/30/2007] [Accepted: 08/31/2007] [Indexed: 11/18/2022]
Abstract
BACKGROUND Segmental allergen challenge is widely used to study mechanisms of human allergic asthma. Despite the relatively large dissemination, limited information is available about the safety of this method. OBJECTIVE Observational, retrospective study to report the adverse events of segmental allergen challenge in a large group of volunteers with asthma. METHODS In total, 78 cases from several studies performed between 1994 and 2007 were pooled for this analysis. Volunteers underwent allergen challenge using either a fixed dose of allergen (7 cases) or an individually standardized allergen dose defined by an inhaled allergen test before the challenge (71 cases). A subgroup of 13 volunteers underwent repeated challenges, with more than 6 months between the challenges. RESULTS With a fixed dose instilled during bronchoscopy, 43% of the participants developed wheezing and coughing, requiring 2-6 puffs of a ss(2)-agonist after segmental allergen challenge. In volunteers with individually standardized doses, a ss(2)-agonist was required in only 19% of the cases. No severe adverse events occurred in all cases studied. Volunteers who underwent repeated challenges did not develop more adverse events than those who underwent 1 challenge. CONCLUSIONS Segmental allergen challenge is a safe tool to study the mechanisms of human allergic asthma, even when repeated challenges are performed in the same patient. It is associated with only a few, tolerable adverse events, especially when the dose of allergen is standardized individually.
Collapse
Affiliation(s)
- Peter Julius
- Department of Pneumology, University of Rostock, Rostock, Germany.
| | | | | | | | | | | | | |
Collapse
|
18
|
Sugiura H, Liu X, Duan F, Kawasaki S, Togo S, Kamio K, Wang XQ, Mao L, Ahn Y, Ertl RF, Bargar TW, Berro A, Casale TB, Rennard SI. Cultured lung fibroblasts from ovalbumin-challenged "asthmatic" mice differ functionally from normal. Am J Respir Cell Mol Biol 2007; 37:424-30. [PMID: 17575074 PMCID: PMC2176123 DOI: 10.1165/rcmb.2007-0089oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Accepted: 06/07/2007] [Indexed: 11/24/2022] Open
Abstract
Asthmatic airway remodeling is characterized by goblet cell hyperplasia, angiogenesis, smooth muscle hypertrophy, and subepithelial fibrosis. This study evaluated whether acquired changes in fibroblast phenotype could contribute to this remodeling. Airway and parenchymal fibroblasts from control or chronically ovalbumin (OVA)-sensitized and challenged "asthmatic" mice were assessed for several functions related to repair and remodeling +/- exogenous transforming growth factor (TGF)-beta. All OVA-challenged mouse fibroblasts demonstrated augmented gel contraction (P < 0.05) and chemotaxis (P < 0.05); increased TGF-beta(1) (P < 0.05), fibronectin (P < 0.05), and vascular endothelial growth factor (P < 0.05) release; and expressed more alpha-smooth muscle actin (P < 0.05). TGF-beta(1) stimulated both control and asthmatic fibroblasts, which retained all differences from control fibroblasts for all features(P < 0.05, all comparisons). Parenchymal fibroblasts proliferated more rapidly (P < 0.05), while airway fibroblasts proliferated similarly compared with control fibroblasts (P = 0.25). Thus, in this animal model, OVA-challenged mouse fibroblasts acquire a distinct phenotype that differs from control fibroblasts. The augmented profibrotic activity and mediator release of asthmatic fibroblasts could contribute to airway remodeling in asthma.
Collapse
Affiliation(s)
- Hisatoshi Sugiura
- Third Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Bossé Y, Rola-Pleszczynski M. Controversy surrounding the increased expression of TGF beta 1 in asthma. Respir Res 2007; 8:66. [PMID: 17892594 PMCID: PMC2078588 DOI: 10.1186/1465-9921-8-66] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 09/24/2007] [Indexed: 01/18/2023] Open
Abstract
Asthma is a waxing and waning disease that leads to structural changes in the airways, such as subepithelial fibrosis, increased mass of airway smooth muscle and epithelial metaplasia. Such a remodeling of the airways futher amplifies asthma symptoms, but its etiology is unknown. Transforming growth factor β1 is a pleiotropic cytokine involved in many fibrotic, oncologic and immunologic diseases and is believed to play an essential role in airway remodeling that occurs in asthmatic patients. Since it is secreted in an inactive form, the overall activity of this cytokine is not exclusively determined by its level of expression, but also by extensive and complex post-translational mechanisms, which are all importanin modulating the magnitude of the TGFβ1 response. Even if TGFβ1 upregulation in asthma is considered as a dogma by certain investigators in the field, the overall picture of the published litterature is not that clear and the cellular origin of this cytokine in the airways of asthmatics is still a contemporaneous debate. On the other hand, it is becoming clear that TGFβ1 signaling is increased in the lungs of asthmatics, which testifies the increased activity of this cytokine in asthma pathogenesis. The current work is an impartial and exhaustive compilation of the reported papers regarding the expression of TGFβ1 in human asthmatics. For the sake of comparison, several studies performed in animal models of the disease are also included. Inconsistencies observed in human studies are discussed and conclusions as well as trends from the current state of the litterature on the matter are proposed. Finally, the different points of regulation that can affect the amplitude of the TGFβ1 response are briefly revised and the possibility that TGFβ1 is disregulated at another level in asthma, rather than simply in its expression, is highlighted.
Collapse
Affiliation(s)
- Ynuk Bossé
- Immunology Division, Department of Pediatrics, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marek Rola-Pleszczynski
- Immunology Division, Department of Pediatrics, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
20
|
Semlali A, Jacques E, Plante S, Biardel S, Milot J, Laviolette M, Boulet LP, Chakir J. TGF-beta suppresses EGF-induced MAPK signaling and proliferation in asthmatic epithelial cells. Am J Respir Cell Mol Biol 2007; 38:202-8. [PMID: 17872498 DOI: 10.1165/rcmb.2007-0031oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Epithelial damage is an important pathophysiologic feature of asthma. Bronchial epithelium damage results in release of growth factors such as transforming growth factor (TGF)-beta(1) that may affect epithelial cell proliferation. The objective of our study is to evaluate the importance of TGF-beta(1) in regulating epithelial cell repair in asthma. We evaluated the effect of TGF-beta(1) on epidermal growth factor (EGF)-induced proliferation and downstream signaling in epithelial cells obtained from subjects with asthma compared with cells from healthy subjects. Cell proliferation was evaluated by bromodeoxyuridine incorporation. EGF receptor (EGFR), mitogen-activated protein kinase, TGF-beta receptors, Smads, Smad anchor for receptor activation (SARA), and cyclin-dependant kinase inhibitors were evaluated by Western blot. TGF-beta(1) and receptor expression were measured by RT-PCR and by enzyme-linked immunosorbent assay. Proliferation of epithelial cells at baseline and after EGF stimulation was significantly reduced in cells derived from subjects with asthma compared with cells obtained from healthy control subjects. EGF-induced ERK1/2 phosphorylation was reduced in epithelial cells from subjects with asthma compared with cells from healthy control subjects. This was paralleled with a reduced EGFR phosphorylation. Addition of TGF-beta(1) significantly decreased EGF-induced cell proliferation. TGF-beta(1) production was higher in asthmatic epithelial cells compared with normal cells. This was supported by a high expression of pSmad 3 and SARA in cells derived from individuals with asthma compared with normal subjects. Cycline-dependent kinase inhibitors were highly expressed in asthmatic compared with normal cells. Inhibition of TGF-beta(1) signaling in asthmatic epithelial cells restored EGFR, ERK1/2 phosphorylation, and cell proliferation induced by EGF. Our results suggest that TGF-beta restrains EGFR phosphorylation and downstream signaling in bronchial epithelial cells.
Collapse
Affiliation(s)
- Abdelhabib Semlali
- Centre de recherche, Hôpital Laval, 2725 Chemin Sainte-Foy, Sainte-Foy, PQ, G1V 4G5 Canada.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
Anticholinergics have been used to treat obstructive respiratory disease for many years from historical preparations of the deadly nightshade genus, to the more recent developments ofipratropium, oxitropium, and tiotropium. The medical treatment of airways obstruction has focused on achieving maximal airway function through bronchodilators. Of the two main bronchodilators, beta2-agonists are often the first treatment choice although there is evidence of equivalence and some suggestions of the superiority of anticholinergics in chronic obstructive pulmonary disease (COPD). The following review looks at the background of anticholinergics, their pharmacological properties, and the evidence for use with suggestions for their place in the treatment of COPD.
Collapse
Affiliation(s)
- Jane E Scullion
- University Hospitals of Leicester Glenfield Site, Institute for Lung Health, Leicester, UK.
| |
Collapse
|
22
|
Kaleli S, Akkaya A, Akdogan M, Gültekin F. The effects of different treatments on prolidase and antioxidant enzyme activities in patients with bronchial asthma. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2006; 22:35-39. [PMID: 21783683 DOI: 10.1016/j.etap.2005.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 11/19/2005] [Indexed: 05/31/2023]
Abstract
The effects of two different treatment combinations of bronchial asthma on antioxidant defense systems and serum prolidase activity were investigated. The groups were organized as follows: the first group (control) consisted of healthy subjects. The second group (treatment 1) consisted of patients with bronchial asthma inhaling budesonide (2×400mcg/d, as puff)+formaterol (2×9mcg/d, as puff). In the third group (treatment 2) patients with bronchial asthma were treated with montelukast (1×10mg/d, as pill)+budesonide (2×400mcg/d, as puff)+formaterol (2×9mcg/d, as puff). The medical therapy of the patients in treatment 1 and treatment 2 lasted 12 weeks. Before and after treatment in all three groups blood samples were taken and the level of thiobarbituric acid-reactive substances (TBARS) and the activities of prolidase, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-Rd) and catalase (CAT) were measured. Prolidase activity was found to be significantly higher in patients compared to control (p<0.05). Treatment 2 was successfully reduced the prolidase activity (p<0.05). Before treatments, SOD activity was significantly decreased whereas TBARS level and other antioxidant enzymes were increased in both treatment groups comparing with control (p<0.05). Both of different treatments given in treatment 1 and treatment 2 groups caused significant increase in SOD whereas decrease in TBARS, CAT, GSSG-Rd, GSH-Px (p<0.05). When compared the treatment groups after treatments, SOD activity was significantly higher in treatment 2 group than treatment 1 group (p<0.05). No significant difference was seen in other parameters. The balance between oxidant-antioxidant system is impaired in patients with asthma.
Collapse
Affiliation(s)
- Süleyman Kaleli
- Isparta Health High School, University of Süleyman Demirel, Isparta, Turkey
| | | | | | | |
Collapse
|
23
|
Choe MM, Sporn PHS, Swartz MA. Extracellular matrix remodeling by dynamic strain in a three-dimensional tissue-engineered human airway wall model. Am J Respir Cell Mol Biol 2006; 35:306-13. [PMID: 16601241 PMCID: PMC2643283 DOI: 10.1165/rcmb.2005-0443oc] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Airway wall remodeling is a hallmark of asthma, characterized by subepithelial thickening and extracellular matrix (ECM) remodeling. Mechanical stress due to hyperresponsive smooth muscle cells may contribute to this remodeling, but its relevance in a three-dimensional environment (where the ECM plays an important role in modulating stresses felt by cells) is unclear. To characterize the effects of dynamic compression in ECM remodeling in a physiologically relevant three-dimensional environment, a tissue-engineered human airway wall model with differentiated bronchial epithelial cells atop a collagen gel containing lung fibroblasts was used. Lateral compressive strain of 10 or 30% at 1 or 60 cycles per hour was applied using a novel straining device. ECM remodeling was assessed by immunohistochemistry and zymography. Dynamic strain, particularly at the lower magnitude, induced airway wall remodeling, as indicated by increased deposition of types III and IV collagen and increased secretion of matrix metalloproteinase-2 and -9. These changes paralleled increased myofibroblast differentiation and were fibroblast-dependent. Furthermore, the spatial pattern of type III collagen deposition correlated with that of myofibroblasts; both were concentrated near the epithelium and decreased diffusely away from the surface, indicating some epithelial control of the remodeling response. Thus, in a physiologically relevant three-dimensional model of the bronchial wall, dynamic compressive strain induced tissue remodeling that mimics many features of remodeling seen in asthma, in the absence of inflammation and dependent on epithelial-fibroblast signaling.
Collapse
Affiliation(s)
- Melanie M Choe
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA
| | | | | |
Collapse
|
24
|
Hastie AT, Wu M, Foster GC, Hawkins GA, Batra V, Rybinski KA, Cirelli R, Zangrilli JG, Peters SP. Alterations in vasodilator-stimulated phosphoprotein (VASP) phosphorylation: associations with asthmatic phenotype, airway inflammation and beta2-agonist use. Respir Res 2006; 7:25. [PMID: 16480498 PMCID: PMC1388207 DOI: 10.1186/1465-9921-7-25] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2005] [Accepted: 02/15/2006] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Vasodilator-stimulated phosphoprotein (VASP) mediates focal adhesion, actin filament binding and polymerization in a variety of cells, thereby inhibiting cell movement. Phosphorylation of VASP via cAMP and cGMP dependent protein kinases releases this "brake" on cell motility. Thus, phosphorylation of VASP may be necessary for epithelial cell repair of damage from allergen-induced inflammation. Two hypotheses were examined: (1) injury from segmental allergen challenge increases VASP phosphorylation in airway epithelium in asthmatic but not nonasthmatic normal subjects, (2) regular in vivo beta2-agonist use increases VASP phosphorylation in asthmatic epithelium, altering cell adhesion. METHODS Bronchial epithelium was obtained from asthmatic and non-asthmatic normal subjects before and after segmental allergen challenge, and after regularly inhaled albuterol, in three separate protocols. VASP phosphorylation was examined in Western blots of epithelial samples. DNA was obtained for beta2-adrenergic receptor haplotype determination. RESULTS Although VASP phosphorylation increased, it was not significantly greater after allergen challenge in asthmatics or normals. However, VASP phosphorylation in epithelium of nonasthmatic normal subjects was double that observed in asthmatic subjects, both at baseline and after challenge. Regularly inhaled albuterol significantly increased VASP phosphorylation in asthmatic subjects in both unchallenged and antigen challenged lung segment epithelium. There was also a significant increase in epithelial cells in the bronchoalveolar lavage of the unchallenged lung segment after regular inhalation of albuterol but not of placebo. The haplotypes of the beta2-adrenergic receptor did not appear to associate with increased or decreased phosphorylation of VASP. CONCLUSION Decreased VASP phosphorylation was observed in epithelial cells of asthmatics compared to nonasthmatic normals, despite response to beta-agonist. The decreased phosphorylation does not appear to be associated with a particular beta2-adrenergic receptor haplotype. The observed decrease in VASP phosphorylation suggests greater inhibition of actin reorganization which is necessary for altering attachment and migration required during epithelial repair.
Collapse
Affiliation(s)
- Annette T Hastie
- Department of Internal Medicine, & Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Min Wu
- Department of Internal Medicine, & Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Gayle C Foster
- Department of Internal Medicine, & Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Gregory A Hawkins
- Department of Internal Medicine, & Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Vikas Batra
- Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Rosemary Cirelli
- Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - James G Zangrilli
- Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Stephen P Peters
- Department of Internal Medicine, & Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| |
Collapse
|
25
|
Busse WW, Wanner A, Adams K, Reynolds HY, Castro M, Chowdhury B, Kraft M, Levine RJ, Peters SP, Sullivan EJ. Investigative bronchoprovocation and bronchoscopy in airway diseases. Am J Respir Crit Care Med 2005; 172:807-16. [PMID: 16020805 PMCID: PMC2718402 DOI: 10.1164/rccm.200407-966ws] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Basic and clinical research strategies used for many lung diseases have depended on volunteer subjects undergoing bronchoscopy to establish access to the airways to collect biological specimens and tissue, perhaps with added bronchoprovocation in asthma syndromes. These procedures have yielded a wealth of important scientific information. Since the last critical review more than a decade ago, some of the techniques and applications have changed, and untoward events have occurred, raising safety concerns and increasing institutional review scrutiny. OBJECTIVES AND METHODS To reappraise these investigational methods in the context of current knowledge, the National Heart, Lung, and Blood Institute and the National Institute of Allergy and Infectious Diseases of the National Institutes of Health convened a working group to review these procedures used for airway disease research, emphasizing asthma and chronic obstructive pulmonary disease. MAIN RESULTS The group reaffirmed the scientific importance of investigative bronchoscopy and bronchoprovocation, even as less invasive technologies evolve. The group also considered the safety of bronchoscopy and bronchoprovocation with methacholine and antigen to be acceptable for volunteer subjects and patients, but stressed the need to monitor this closely and to emphasize proper training of participating medical research personnel. Issues were raised about vulnerable volunteers, especially children who need surrogates for informed consent. CONCLUSION This review of investigative bronchoscopy and bronchoprovocation could serve as the basis for future guidelines for the use of these procedures in the United States.
Collapse
|
26
|
Kumar RK, Herbert C, Kasper M. Reversibility of airway inflammation and remodelling following cessation of antigenic challenge in a model of chronic asthma. Clin Exp Allergy 2005; 34:1796-802. [PMID: 15544607 DOI: 10.1111/j.1365-2222.2004.02097.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Asthma is associated with recruitment of eosinophils, accumulation of chronic inflammatory cells in the airway walls, subepithelial fibrosis and other structural changes of airway wall remodelling. The role of ongoing exposure to allergens in their pathogenesis remains unclear. OBJECTIVE To examine whether changes of inflammation and remodelling were reversible following cessation of antigenic challenge in a mouse model of chronic asthma. METHODS BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged by inhalation of a low mass concentration of antigen for 8 weeks, leading to development of acute-on-chronic airway inflammation, subepithelial fibrosis and other changes of airway wall remodelling. Epithelial injury was assessed by immunohistochemistry, while inflammation and remodelling were quantified by appropriate histomorphometric techniques. Regression of lesions was assessed in animals examined at 1, 2 and 4 weeks after exposure to OVA ceased. RESULTS We did not find evidence of airway epithelial injury in this model of low-level chronic inhalational exposure to antigen. Persistence of the recruitment of eosinophils and chronic inflammatory cells in the airway walls was dependent on continuing antigenic challenge, as was persistence of mucous cell hyperplasia/metaplasia. Subepithelial fibrosis and epithelial hypertrophy exhibited delayed reversibility following cessation of exposure to antigen, possibly related to matrix-associated accumulation of transforming growth factor-beta(1). CONCLUSION In chronic asthma, low-level antigenic challenge may be required to maintain the inflammatory response in the airway wall, but airway remodelling may persist in its absence.
Collapse
Affiliation(s)
- R K Kumar
- Department of Pathology, University of New South Wales, Sydney, Australia.
| | | | | |
Collapse
|
27
|
Kelly MM, Leigh R, Bonniaud P, Ellis R, Wattie J, Smith MJ, Martin G, Panju M, Inman MD, Gauldie J. Epithelial expression of profibrotic mediators in a model of allergen-induced airway remodeling. Am J Respir Cell Mol Biol 2004; 32:99-107. [PMID: 15563691 DOI: 10.1165/rcmb.2004-0190oc] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Airway remodeling, including subepithelial fibrosis, is a characteristic feature of asthma and likely contributes to the pathogenesis of airway hyperresponsiveness. We examined expression of genes related to airway wall fibrosis in a model of chronic allergen-induced airway dysfunction using laser capture microdissection and quantitative real-time PCR. BALB/c mice were sensitized and subjected to chronic ovalbumin exposure over a 12-wk period, after which they were rested and then harvested 2 and 8 wk after the last exposure. Chronic allergen-exposed mice had significantly increased indices of airway remodeling and airway hyperreactivity at all time points, although no difference in expression of fibrosis-related genes was found when mRNA extracted from whole lung was examined. In contrast, fibrosis-related gene expression was significantly upregulated in mRNA obtained from microdissected bronchial wall at 2 wk after chronic allergen exposure. In addition, when bronchial wall epithelium and smooth muscle were separately microdissected, gene expression of transforming growth factor-beta1 and plasminogen activating inhibitor-1 were significantly upregulated only in the airway epithelium. These data suggest that transforming growth factor-beta1 and other profibrotic mediators produced by airway wall, and specifically, airway epithelium, play an important role in the pathophysiology of airway remodeling.
Collapse
Affiliation(s)
- Margaret M Kelly
- Department of Pathology and Molecular Medicine, Centre for Gene Therapeutics, MDCL-4017, McMaster University, 1200 Main Street West, Hamilton, ON L8N 3Z5, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Asakura T, Ishii Y, Chibana K, Fukuda T. Leukotriene D4 stimulates collagen production from myofibroblasts transformed by TGF-beta. J Allergy Clin Immunol 2004; 114:310-5. [PMID: 15316508 DOI: 10.1016/j.jaci.2004.04.037] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Airway remodeling has an important role in the pathogenesis of bronchial asthma. Many mediators that influence the pathophysiology of bronchial asthma, especially cysteinyl leukotrienes (CysLTs) and TGF-beta1, are involved in airway remodeling. OBJECTIVE To know whether TGF-beta1 alters fibroblast responsiveness to CysLTs, we examined the effects of leukotriene (LT) D4 on collagen production from fibroblasts and from myofibroblasts transformed by TGF-beta1. We also examined whether TGF-beta1 upregulates CysLT1 receptor (CysLT1R) expression in fibroblasts. METHODS Concentrations of procollagen in the human fetal lung fibroblast (HFL) 1 cell supernatant were measured by using an enzyme immunoassay kit in the presence or absence of various concentrations of LTD4, TGF-beta1, CysLT1R antagonist, or some combination of these. The mRNA expression of CysLT1R and alpha-smooth muscle actin as a marker of myofibroblasts was measured by means of real-time PCR. Furthermore, protein expression of CysLT1R on fibroblasts was measured by means of flow cytometric analysis. RESULTS TGF-beta1 stimulated collagen production from HFL-1 cells, but LTD4 alone did not. LTD4 in combination with TGF-beta1 increased collagen production compared with TGF-beta1 alone. Real-time PCR showed that stimulation with TGF-beta1 significantly upregulated CysLT1R and alpha-smooth muscle actin mRNA expression in HFL-1 cells. CONCLUSIONS LTD4 increased collagen production by upregulating CysLT1R induced by TGF-beta1. In the TGF-beta-rich milieu, activated myofibroblasts expressing CysLT1R can respond to CysLTs and produce large amounts of extracellular matrix, thereby contributing to airway remodeling. These data suggest that treatment with leukotriene receptor antagonists might prevent airway remodeling in patients with asthma.
Collapse
Affiliation(s)
- Takuma Asakura
- Department of Pulmonary Medicine and Clinical Immunology, Dokkyo University School of Medicine, Japan
| | | | | | | |
Collapse
|
29
|
Kumar RK, Herbert C, Foster PS. Expression of growth factors by airway epithelial cells in a model of chronic asthma: regulation and relationship to subepithelial fibrosis. Clin Exp Allergy 2004; 34:567-75. [PMID: 15080809 DOI: 10.1111/j.1365-2222.2004.1917.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Growth factors produced by airway epithelial cells may be important in the pathogenesis of subepithelial fibrosis, a distinctive lesion of chronic human asthma. OBJECTIVE To examine the relationship between the development of subepithelial fibrosis and the expression of transforming growth factor-beta 1 (TGF-beta 1) and ligands for the epidermal growth factor receptor. METHODS BALB/c mice sensitized to ovalbumin were chronically challenged by inhalation of low levels of antigen, leading to development of subepithelial fibrosis and other changes of airway wall remodelling. Growth factor expression was assessed by immunohistochemistry and enzyme immunoassay. RESULTS Allergic sensitization directly correlated with airway epithelial expression of both the cleaved, potentially biologically active form of TGF-beta 1 and of amphiregulin in response to allergen challenge. Accumulation of TGF-beta 1 was related to remodelling of the airway wall in chronic asthma, whereas expression of amphiregulin did not exhibit a similar relationship. Production of epithelial cell-derived TGF-beta 1 appeared to be regulated by IL-13, while both IL-13 and CD4(+) T cells regulated accumulation of TGF-beta 1. In contrast to results reported in high-level exposure models of airway fibrosis, eosinophils did not appear to be a significant source of TGF-beta 1. CONCLUSION Airway epithelial cell-derived TGF-beta 1 has a potentially crucial role in the development of airway wall remodelling in asthma. Immunological mechanisms may regulate the release and accumulation of TGF-beta 1.
Collapse
Affiliation(s)
- R K Kumar
- Department of Pathology, University of New South Wales, Sydney, Australia.
| | | | | |
Collapse
|
30
|
Evans MJ, Fanucchi MV, Baker GL, Van Winkle LS, Pantle LM, Nishio SJ, Schelegle ES, Gershwin LJ, Miller LA, Hyde DM, Plopper CG. The remodelled tracheal basement membrane zone of infant rhesus monkeys after 6 months of recovery. Clin Exp Allergy 2004; 34:1131-6. [PMID: 15248862 DOI: 10.1111/j.1365-2222.2004.02004.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND In previous studies, we showed that repeated exposure to (1) house dust mite allergen (HDMA) (Dermatophagoides farinae) caused thickening of the basement membrane zone (BMZ) and (2) HDMA+ozone (O3) caused depletion of BMZ perlecan and atypical development of BMZ collagen (irregular thin areas<2.0 microm in width). OBJECTIVE The purpose of this study was to determine if these remodelling changes were reversible after 6 months of recovery. METHODS Rhesus monkeys were exposed to a regimen of HDMA and or O3 or filtered air (FA) for 6 months. After the exposure protocol was completed FA and O3 groups were allowed to recover in FA for 6 months. The HDMA and HDMA+O3 exposure groups recovered in a modified environment. They were re-exposed to HDMA aerosol for 2 h at monthly intervals during recovery in order to maintain sensitization for pulmonary function testing. To detect structural changes in the BMZ, collagen I and perlecan immunoreactivity were measured and compared to data from the previous papers. RESULTS The remodelled HDMA group had a significantly thicker BMZ and after 6 months of recovery the width had not regressed. In the remodelled BMZ of the HDMA+O3 group, perlecan had returned to the BMZ after 6 months of the recovery protocol, and the thin, irregular, collagen BMZ had been resolved. CONCLUSION In summary, this study has shown that: (1) The width of the remodelled HDMA BMZ did not regress during a recovery protocol that included a sensitizing dose of HDMA. (2) The atypical collagen BMZ in the HDMA+O3 BMZ was resolved in the absence of O3. (3) Depletion of perlecan from the BMZ by O3 was reversed by recovery in the absence of O3.
Collapse
Affiliation(s)
- M J Evans
- Department of Anatomy, Physiology & Cell Biology; Center for Comparative Respiratory Biology and Medicine, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Mitchell HW, Turner DJ, Noble PB. Cholinergic responsiveness of the individual airway after allergen instillation in sensitised pigs. Pulm Pharmacol Ther 2004; 17:81-8. [PMID: 15123229 DOI: 10.1016/j.pupt.2003.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Revised: 09/12/2003] [Accepted: 10/09/2003] [Indexed: 11/18/2022]
Abstract
Allergen exposure of sensitised lungs produces bronchial hyperresponsiveness in vivo associated with airway inflammation and remodelling. It is unclear if hyperresponsiveness is also present in airways in vitro under similar conditions of drug provocation as carried out in vivo, and at different times after allergen-challenge. This study records responsiveness of individual airway segments to acetylcholine (ACh) in sensitised bronchi after instillation of allergen (ovalbumin, OA). Airway histology and sensitivity and maximum effects to ACh were recorded 1, 24 and 72 h and 1 week after OA. OA-instilled airways exhibited eosinophilia and epithelial proliferation. Physiological recordings showed no change in maximum contractions of airway segments to acetylcholine placed in the airway lumen except at 24 h where they were reduced. In contrast maximum contractions to ACh to the airway adventitia were reduced at all times except 1 week, with the greatest change occurring at 24 h. There were no changes in airway sensitivity to either route of ACh in OA-instilled airways but the difference in sensitivity to adventitial and lumenal ACh was reduced. Results show that allergen does not produce hyperresponsiveness at the airway wall but it may alter an interaction between airway smooth muscle and other structural components of the airway.
Collapse
Affiliation(s)
- H W Mitchell
- Physiology, School of Biomedical and Chemical Sciences, University of Western Australia, and Western Australian Institute for Medical Research, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia.
| | | | | |
Collapse
|
32
|
Batra V, Musani AI, Hastie AT, Khurana S, Carpenter KA, Zangrilli JG, Peters SP. Bronchoalveolar lavage fluid concentrations of transforming growth factor (TGF)-beta1, TGF-beta2, interleukin (IL)-4 and IL-13 after segmental allergen challenge and their effects on alpha-smooth muscle actin and collagen III synthesis by primary human lung fibroblasts. Clin Exp Allergy 2004; 34:437-44. [PMID: 15005738 DOI: 10.1111/j.1365-2222.2004.01885.x] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
RATIONALE Asthmatic airway remodelling is characterized by myofibroblast hyperplasia and subbasement membrane collagen deposition. We hypothesized that cytokines and growth factors implicated in asthmatic airway remodelling are increased in bronchoalveolar lavage (BAL) fluid of asthmatics after segmental allergen challenge (SAC), and that these growth factors and cytokines increase alpha-smooth muscle actin (alpha-SMA) and collagen III synthesis by human lung fibroblasts (HLFs). METHODS Transforming growth factor (TGF)-beta1, TGF-beta2, IL-4 and IL-13 levels were measured in BAL fluid from 10 asthmatics and 9 non-asthmatic controls at baseline and then 1 day, 1 week and 2 weeks after SAC. Confluent cultures of HLFs were stimulated by exogenous addition of TGF-beta1, TGF-beta2, IL-4 or IL-13 (concentration range 0.01-10 ng/mL) over 48 h. Collagen III was measured in culture supernates and alpha-SMA in cell lysates by Western blot. RESULTS At baseline, there was no difference in BAL fluid concentrations of TGF-beta1, IL-4 and IL-13 between asthmatics and controls; however, non-asthmatics had higher concentrations of total TGF-beta2. In asthmatics, BAL fluid concentrations of all four factors increased significantly 1 day after SAC. TGF-beta1, TGF-beta2 and IL-13 concentrations returned to baseline by 1 week after SAC, but BAL fluid IL-4 concentration remained elevated for at least 2 weeks. TGF-beta1, TGF-beta2 and IL-4 significantly increased alpha-SMA in fibroblasts, but only IL-4 caused corresponding increases in collagen III synthesis. IL-13 had no direct effects on collagen III synthesis and alpha-SMA expression. CONCLUSIONS Because IL-4 caused a dose-dependent increase in alpha-SMA and collagen III synthesis, it may be an important cytokine mediating asthmatic airway remodelling. TGF-beta1 and TGF-beta2 may also play a role in airway remodelling by stimulating phenotypic change of fibroblasts to myofibroblasts. Additionally, collagen III synthesis appears to be independent of myofibroblast phenotype and is apparently regulated by different growth factors and cytokines.
Collapse
Affiliation(s)
- V Batra
- Department of Medicine, Division of Critical Care, Pulmonary, Allergic and Immunologic Diseases, Thomas Jefferson University, Philadelphia, PA, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
The major function of the respiratory epithelium was once thought to be that of a physical barrier. However, it constitutes the interface between the internal milieu and the external environment as well as being a primary target for inhaled respiratory drugs. It also responds to changes in the external environment by secreting a large number of molecules and mediators that signal to cells of the immune system and underlying mesenchyme. Thus, the epithelium is in a unique position to translate gene-environment interactions. Normally, the epithelium has a tremendous capacity to repair itself following injury. However, evidence is rapidly accumulating to show that the airway epithelium of asthmatics is abnormal and has increased susceptibility to injury compared to normal epithelium. Areas of detachment and fragility are a characteristic feature not observed in other inflammatory diseases such as COPD. In addition to being more susceptible to damage, normal repair processes are also compromised. Failure of appropriate growth and differentiation of airway epithelial cells will cause persistent mucosal injury. The response to traditional therapy such as glucocorticoids may also be compromised. However, whether the differences observed in asthmatic epithelium are a cause of or secondary to the development of the disease remains unanswered. Strategies to address this question include careful examination of the ontogeny of the disease in children and use of gene array technology should provide some important answers, as well as allow a better understanding of the critical role that the epithelium plays under normal conditions and in diseases such as asthma.
Collapse
Affiliation(s)
- Darryl A Knight
- Asthma and Allergy Research Institute, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
| | | |
Collapse
|
34
|
Abstract
Increased airway smooth muscle mass has been demonstrated in patients with asthma, bronchopulmonary dysplasia and most recently, cystic fibrosis. These observations emphasize the need for further knowledge of the events involved in airway smooth muscle mitogenesis and hypertrophy. Workers in the field have developed cell culture systems involving tracheal and bronchial myocytes from different species. An emergent body of literature indicates that mutual signal transduction pathways control airway smooth muscle cell cycle entry across species lines. This article reviews what is known about mitogen-activated signal transduction in airway myocytes. The extracellular signal regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI 3-kinase) pathways appear to be key positive regulators of airway smooth muscle mitogenesis; recent studies have also demonstrated specific roles for reactive oxygen and the JAK/STAT pathway. It is also possible that growth factor stimulation of airway smooth muscle concurrently elicits signaling through negative regulatory intermediates such as p38 mitogen-activated protein (MAP) kinase and protein kinase C (PKC) delta, conceivably as a defense against extreme growth.
Collapse
Affiliation(s)
- Limei Zhou
- Department of Pediatrics, University of Chicago, Chicago, IL 48109-0688, USA
| | | |
Collapse
|
35
|
Nikolaidis NM, Zimmermann N, King NE, Mishra A, Pope SM, Finkelman FD, Rothenberg ME. Trefoil factor-2 is an allergen-induced gene regulated by Th2 cytokines and STAT6 in the lung. Am J Respir Cell Mol Biol 2003; 29:458-64. [PMID: 12702542 DOI: 10.1165/rcmb.2002-0309oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Asthma, a complex chronic inflammatory pulmonary disorder, is on the rise despite intense ongoing research, underscoring the need for new scientific inquiry. In an effort to provide unbiased insight into the pathogenesis of this disease, we took an empirical approach involving transcript expression profiling of lung tissue from mice with experimental asthma. Employing asthma models induced by different allergens (ovalbumin [OVA] and Aspergillus fumigatus), we found strong induction of trefoil factor-2 (TFF2), a gene involved in epithelial restitution and mucosal secretion in the gastrointestinal tract. Using a combination of pharmacologic delivery and transgenic overexpression, TFF2 was demonstrated to be strongly induced in the lung by interleukin (IL)-4 and IL-13. Notably, TFF2 induction by both OVA and pharmacologic delivery of IL-4 and IL-13 was dependent upon signal transducer and activator of transcription (STAT)6. However, the upregulation of TFF2 by both chronic expression of IL-4 and Aspergillus fumigatus antigen was independent of STAT6. These results establish that TFF2 is an allergen-induced lung gene product differentially regulated by Th2 cytokines and STAT6. Given the important role of trefoil factors in wound healing, epithelial restitution, and maintenance of mucosal integrity in the gastrointestinal tract, these results support a potential role for TFF2, in both the acute and chronic phase of experimental asthma, via separate induction pathways.
Collapse
Affiliation(s)
- Nikolaos M Nikolaidis
- Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7028 Cincinnati, OH 45229, USA
| | | | | | | | | | | | | |
Collapse
|
36
|
Jagnow J, Clegg S. Klebsiella pneumoniae MrkD-mediated biofilm formation on extracellular matrix- and collagen-coated surfaces. MICROBIOLOGY (READING, ENGLAND) 2003; 149:2397-2405. [PMID: 12949165 DOI: 10.1099/mic.0.26434-0] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The type 3 fimbriae of Klebsiella pneumoniae are comprised of the major fimbrial subunit (MrkA) and the adhesin (MrkD) that has previously been shown to mediate binding to collagen. The ability of adhesive and non-adhesive derivatives of K. pneumoniae to form biofilms on collagen-coated surfaces in continuous-flow chambers was investigated. Unlike biofilm formation on abiotic plastic surfaces, the presence of the MrkD adhesin was necessary for growth on collagen-coated surfaces. Fimbriate strains lacking the MrkD adhesin did not efficiently adhere to and grow on these surfaces. Similarly, purified human extracellular matrix and the extracellular matrix formed by human bronchial epithelial cells grown in vitro provided a suitable substrate for MrkD-mediated biofilm formation, whereas direct binding to the respiratory cells was not observed. Type 3 fimbriae may therefore have two roles in the early stages of adherence and growth on in-dwelling devices such as endotracheal tubes. The MrkA polypeptide could facilitate adsorption to abiotic polymers of recently implanted devices and the MrkD adhesin could enable bacteria to adhere to and grow on polymers coated with host-derived proteins.
Collapse
Affiliation(s)
- Jennifer Jagnow
- Department of Microbiology, College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Steven Clegg
- Department of Microbiology, College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| |
Collapse
|
37
|
Affiliation(s)
- J Mark Madison
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605-2324, USA.
| |
Collapse
|
38
|
Ricciardolo FLM, Di Stefano A, van Krieken JHJM, Sont JK, van Schadewijk A, Rabe KF, Donner CF, Hiemstra PS, Sterk PJ, Mauad T. Proliferation and inflammation in bronchial epithelium after allergen in atopic asthmatics. Clin Exp Allergy 2003; 33:905-11. [PMID: 12859446 DOI: 10.1046/j.1365-2222.2003.01686.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND The mechanisms that regulate epithelial integrity and repair in asthma are poorly understood. We hypothesized that allergen exposure could alter epithelial inflammation, damage and proliferation in atopic asthma. OBJECTIVE We studied epithelial cell infiltration, shedding, expression of the proliferation marker Ki-67 and the epithelial cell-cell adhesion molecules Ep-CAM and E-cadherin in bronchial biopsies of 10 atopic mild asthmatics 48 h after experimental diluent (D) and allergen (A) challenge in a cross-over design. METHODS Epithelial shedding, expressed as percentage of not intact epithelium, Ki-67+, eosinophil/EG-2+, CD4+ and CD8+ cells were quantified by image analysis in bronchial epithelium, and adhesion molecules were analysed semi-quantitatively. RESULTS Epithelial shedding was not altered by A (D: 88.1+/-3.1% vs. A: 89.2+/-3.7%; P=0.63). The numbers of Ki-67+ epithelial (D: 10.2+/-0.2 vs. A: 19.9+/-0.3 cells/mm; P=0.03), EG-2+ (D: 4.3+/-0.5 vs. A: 27+/-0.3 cells/mm; P=0.04) and CD4+ cells (D: 1.7+/-1.2 vs. A: 12.3+/-0.6 cells/mm; P=0.04) were significantly increased after A, whilst CD8+ numbers were not significantly changed (P>0.05). E-cadherin and Ep-CAM epithelial staining showed a similar intensity after D and A (P>0.05). We found a positive correlation between EG-2+ and Ki-67+ cells in the epithelium (Rs: 0.63; P=0.02). CONCLUSION Our study indicates that allergen challenge increases epithelial proliferation in conjunction with inflammation at 2 days after exposure. This favours the hypothesis that long-lasting epithelial restitution is involved in the pathogenesis of asthma.
Collapse
Affiliation(s)
- F L M Ricciardolo
- Department of Pulmonology, Leiden University Medical Center, The Netherlands.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Pelaia G, Cuda G, Vatrella A, Fratto D, Grembiale RD, Tagliaferri P, Maselli R, Costanzo FS, Marsico SA. Effects of transforming growth factor-[beta] and budesonide on mitogen-activated protein kinase activation and apoptosis in airway epithelial cells. Am J Respir Cell Mol Biol 2003; 29:12-8. [PMID: 12600835 DOI: 10.1165/rcmb.2002-0074oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Airway epithelial cells play a central role in the inflammatory, apoptotic, and remodeling processes associated with asthma. Within this context, a key function is exerted by transforming growth factor-beta (TGF-beta), whose biological effects are mediated at least in part by mitogen-activated protein kinases (MAPKs). The aim of our study was to investigate, in primary cultures of human bronchial epithelial cells (HBEC), the effects of TGF-beta (10 ng/ml) on both MAPK activation and apoptosis, in the presence or absence of a pretreatment with budesonide (10-8 M). MAPK activation was detected by Western blotting, using anti-phospho-MAPK monoclonal antibodies, which specifically recognize the phosphorylated, active forms of these enzymes. Apoptosis was assayed by caspase-3 activation and fluorescence microscopy, using annexin-V (An-V) and propidium iodide (PI) as markers of cell death. Our results show that TGF-beta induced a marked ( reverse similar 9-fold) increase in p38 MAPK phosphorylation, and also dramatically enhanced cell death, which was completely prevented by specific MAPK inhibitors. Both MAPK activation and apoptosis were effectively inhibited by budesonide (BUD), thereby suggesting that the powerful antiapoptotic action of inhaled glucocorticoids may be very important for their protective role against epithelial injury, which represents a key pathogenic event in asthma.
Collapse
Affiliation(s)
- Girolamo Pelaia
- Department of Experimental and Clinical Medicine, University of "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Pelaia G, Vatrella A, Cuda G, Maselli R, Marsico SA. Molecular mechanisms of corticosteroid actions in chronic inflammatory airway diseases. Life Sci 2003; 72:1549-61. [PMID: 12551744 DOI: 10.1016/s0024-3205(02)02446-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although corticosteroids have been used for a long time as a very effective therapy of airway inflammatory diseases such as asthma, only recently the molecular basis of their mechanism of action has begun to be elucidated. These hormones exert their biological and pharmacological actions by binding to cytoplasmic receptors that, upon activation, translocate to the nucleus where they interact with specific genomic sequences thus modulating gene expression. However, many glucocorticoid effects responsible for their anti-inflammatory and anti-asthmatic activity take place irrespectively of receptor binding to DNA. In particular, ligand-bound glucocorticoid receptors can repress several different pro-inflammatory genes by physically associating, via protein-protein interactions, with various transcription factors and with the macromolecular complexes implicated in regulation of chromatin structure and function. In this regard, an important role is played by the influences of corticosteroids on the intrinsic histone acetyltransferase and deacetylase functions of coactivators and corepressors, respectively. Furthermore, the signal transduction pathways mediated by mitogen-activated protein kinases are newly recognized, key targets of glucocorticoids. Indeed, these enzymatic cascades are crucially involved in the regulation of gene expression in that they are essential for the activity of a high number of transcription factors. Therefore, the recent advances made in such a rapidly growing research field are providing new insights into the mode of action of corticosteroids, thereby also unveiling novel promising therapeutic strategies directly targeted to the molecular events underlying the inflammatory, immune, and apoptotic processes implicated in the pathogenesis of asthma and other airway diseases.
Collapse
Affiliation(s)
- G Pelaia
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Catanzaro, Italy.
| | | | | | | | | |
Collapse
|
41
|
Tobin MJ. Asthma, airway biology, and nasal disorders in AJRCCM 2002. Am J Respir Crit Care Med 2003; 167:319-32. [PMID: 12554621 DOI: 10.1164/rccm.2212007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Loyola University of Chicago Stritch School of Medicine and Hines Veterans Affairs Hospital, Hines, Illinois 60141, USA.
| |
Collapse
|