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Gomez HM, Haw TJ, Ilic D, Robinson P, Donovan C, Croft AJ, Vanka KS, Small E, Carroll OR, Kim RY, Mayall JR, Beyene T, Palanisami T, Ngo DTM, Zosky GR, Holliday EG, Jensen ME, McDonald VM, Murphy VE, Gibson PG, Horvat JC. Landscape fire smoke airway exposure impairs respiratory and cardiac function and worsens experimental asthma. J Allergy Clin Immunol 2024; 154:209-221.e6. [PMID: 38513838 DOI: 10.1016/j.jaci.2024.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 02/13/2024] [Accepted: 02/22/2024] [Indexed: 03/23/2024]
Abstract
BACKGROUND Millions of people are exposed to landscape fire smoke (LFS) globally, and inhalation of LFS particulate matter (PM) is associated with poor respiratory and cardiovascular outcomes. However, how LFS affects respiratory and cardiovascular function is less well understood. OBJECTIVE We aimed to characterize the pathophysiologic effects of representative LFS airway exposure on respiratory and cardiac function and on asthma outcomes. METHODS LFS was generated using a customized combustion chamber. In 8-week-old female BALB/c mice, low (25 μg/m3, 24-hour equivalent) or moderate (100 μg/m3, 24-hour equivalent) concentrations of LFS PM (10 μm and below [PM10]) were administered daily for 3 (short-term) and 14 (long-term) days in the presence and absence of experimental asthma. Lung inflammation, gene expression, structural changes, and lung function were assessed. In 8-week-old male C57BL/6 mice, low concentrations of LFS PM10 were administered for 3 days. Cardiac function and gene expression were assessed. RESULTS Short- and long-term LFS PM10 airway exposure increased airway hyperresponsiveness and induced steroid insensitivity in experimental asthma, independent of significant changes in airway inflammation. Long-term LFS PM10 airway exposure also decreased gas diffusion. Short-term LFS PM10 airway exposure decreased cardiac function and expression of gene changes relating to oxidative stress and cardiovascular pathologies. CONCLUSIONS We characterized significant detrimental effects of physiologically relevant concentrations and durations of LFS PM10 airway exposure on lung and heart function. Our study provides a platform for assessment of mechanisms that underpin LFS PM10 airway exposure on respiratory and cardiovascular disease outcomes.
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Affiliation(s)
- Henry M Gomez
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Tatt J Haw
- Heart and Stroke Research Program, Hunter Medical Research Institute, New Lambton Heights, Newcastle, Australia; College of Health, Medicine, and Wellbeing, Centre of Excellence Newcastle Cardio-Oncology Research Group, University of Newcastle, Callaghan, Newcastle, Australia
| | - Dusan Ilic
- Newcastle Institute for Energy and Resources, University of Newcastle, Callaghan, Australia
| | - Peter Robinson
- Newcastle Institute for Energy and Resources, University of Newcastle, Callaghan, Australia
| | - Chantal Donovan
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia; School of Life Sciences, University of Technology Sydney, Faculty of Science, Sydney, Australia
| | - Amanda J Croft
- Heart and Stroke Research Program, Hunter Medical Research Institute, New Lambton Heights, Newcastle, Australia; College of Health, Medicine, and Wellbeing, Centre of Excellence Newcastle Cardio-Oncology Research Group, University of Newcastle, Callaghan, Newcastle, Australia
| | - Kanth S Vanka
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia; Newcastle Institute for Energy and Resources, University of Newcastle, Callaghan, Australia
| | - Ellen Small
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Olivia R Carroll
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Richard Y Kim
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia; School of Life Sciences, University of Technology Sydney, Faculty of Science, Sydney, Australia
| | - Jemma R Mayall
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Tesfalidet Beyene
- School of Medicine and Public Health, University of Newcastle and Asthma and Breathing Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Thava Palanisami
- Global Innovative Centre for Advanced Nanomaterials, University of Newcastle, Callaghan, Australia
| | - Doan T M Ngo
- Heart and Stroke Research Program, Hunter Medical Research Institute, New Lambton Heights, Newcastle, Australia; College of Health, Medicine, and Wellbeing, Centre of Excellence Newcastle Cardio-Oncology Research Group, University of Newcastle, Callaghan, Newcastle, Australia
| | - Graeme R Zosky
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia; College of Health and Medicine, Tasmanian School of Medicine, University of Tasmania, Hobart, Australia
| | - Elizabeth G Holliday
- School of Medicine and Public Health, University of Newcastle, Callaghan, Australia
| | - Megan E Jensen
- School of Medicine and Public Health, University of Newcastle and Asthma and Breathing Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Vanessa M McDonald
- School of Medicine and Public Health, University of Newcastle and Asthma and Breathing Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Vanessa E Murphy
- School of Medicine and Public Health, University of Newcastle and Asthma and Breathing Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Peter G Gibson
- School of Medicine and Public Health, University of Newcastle and Asthma and Breathing Program, Hunter Medical Research Institute, Newcastle, Australia
| | - Jay C Horvat
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Immune Health Program, Hunter Medical Research Institute, Newcastle, Australia.
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Yu L, Qiu C, Chen R. A narrative review of research advances in the study of molecular markers of airway smooth muscle cells. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:375. [PMID: 35434039 PMCID: PMC9011254 DOI: 10.21037/atm-22-800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/16/2022] [Indexed: 11/06/2022]
Abstract
Background and Objective Airway smooth muscle cells (ASMCs) are an important component of the airway. Their thickening and proliferation are important in pathological situations, such as airway remodeling in asthma, but their origin remains unclear. Therefore, characterizing molecular markers of ASMCs were sought to identify the source of increased ASMCs in asthmatic airway remodeling. Methods Articles for this review were derived from a review of the literature related to surface markers and biological properties of ASMCs and smooth muscle cells (SMCs) using PubMed, Google Scholar, and Web of Science. Key Content and Findings This review discusses several SMC molecular markers, describes the different developmental stages of SMCs that express different molecular markers, and summarizes several classical SMC molecular markers. However, the establishment of a specific molecular marker detection system for ASMCs still faces great challenges. Conclusions Although there is no recognized molecular marker detection system for ASMCs, and the study of the properties and sources of increased ASMCs in asthma airway remodeling is still in a state of exploration, the future is promising. Among the SMC markers described in this review, Myosin heavy chain 11 (MYH11) is a molecular marker for mature SMCs and Transgelin (TAGLN) is an early marker for SMC differentiation, and different molecular markers or combinations of molecular markers can be selected for the identification of the properties and sources of increased ASMCs in asthma airway remodeling according to the differentiation period and research needs.
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Affiliation(s)
- Li Yu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital (Shenzhen People's Hospital), School of Medicine, Southern University of Science and Technology, Shenzhen Institute of Respiratory Diseases, Shenzhen, China
| | - Chen Qiu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital (Shenzhen People's Hospital), School of Medicine, Southern University of Science and Technology, Shenzhen Institute of Respiratory Diseases, Shenzhen, China
| | - Rongchang Chen
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital (Shenzhen People's Hospital), School of Medicine, Southern University of Science and Technology, Shenzhen Institute of Respiratory Diseases, Shenzhen, China
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Wang ZN, Su RN, Yang BY, Yang KX, Yang LF, Yan Y, Chen ZG. Potential Role of Cellular Senescence in Asthma. Front Cell Dev Biol 2020; 8:59. [PMID: 32117985 PMCID: PMC7026390 DOI: 10.3389/fcell.2020.00059] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/22/2020] [Indexed: 12/18/2022] Open
Abstract
Cellular senescence is a complicated process featured by irreversible cell cycle arrest and senescence-associated secreted phenotype (SASP), resulting in accumulation of senescent cells, and low-grade inflammation. Cellular senescence not only occurs during the natural aging of normal cells, but also can be accelerated by various pathological factors. Cumulative studies have shown the role of cellular senescence in the pathogenesis of chronic lung diseases including chronic obstructive pulmonary diseases (COPD) and idiopathic pulmonary fibrosis (IPF) by promoting airway inflammation and airway remodeling. Recently, great interest has been raised in the involvement of cellular senescence in asthma. Limited but valuable data has indicated accelerating cellular senescence in asthma. This review will compile current findings regarding the underlying relationship between cellular senescence and asthma, mainly through discussing the potential mechanisms of cellular senescence in asthma, the impact of senescent cells on the pathobiology of asthma, and the efficiency and feasibility of using anti-aging therapies in asthmatic patients.
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Affiliation(s)
- Zhao-Ni Wang
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Ruo-Nan Su
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Bi-Yuan Yang
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ke-Xin Yang
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Li-Fen Yang
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yan Yan
- Guangdong Provincial Key Laboratory of Biomedical Imaging, Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China.,Center for Interventional Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Zhuang-Gui Chen
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Jaslove JM, Nelson CM. Smooth muscle: a stiff sculptor of epithelial shapes. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170318. [PMID: 30249770 PMCID: PMC6158200 DOI: 10.1098/rstb.2017.0318] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2018] [Indexed: 12/11/2022] Open
Abstract
Smooth muscle is increasingly recognized as a key mechanical sculptor of epithelia during embryonic development. Smooth muscle is a mesenchymal tissue that surrounds the epithelia of organs including the gut, blood vessels, lungs, bladder, ureter, uterus, oviduct and epididymis. Smooth muscle is stiffer than its adjacent epithelium and often serves its morphogenetic function by physically constraining the growth of a proliferating epithelial layer. This constraint leads to mechanical instabilities and epithelial morphogenesis through buckling. Smooth muscle stiffness alone, without smooth muscle cell shortening, seems to be sufficient to drive epithelial morphogenesis. Fully understanding the development of organs that use smooth muscle stiffness as a driver of morphogenesis requires investigating how smooth muscle develops, a key aspect of which is distinguishing smooth muscle-like tissues from one another in vivo and in culture. This necessitates a comprehensive appreciation of the genetic, anatomical and functional markers that are used to distinguish the different subtypes of smooth muscle (for example, vascular versus visceral) from similar cell types (including myofibroblasts and myoepithelial cells). Here, we review how smooth muscle acts as a mechanical driver of morphogenesis and discuss ways of identifying smooth muscle, which is critical for understanding these morphogenetic events.This article is part of the Theo Murphy meeting issue 'Mechanics of Development'.
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Affiliation(s)
- Jacob M Jaslove
- Department of Molecular Biology, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ 08544, USA
- Graduate School of Biomedical Sciences, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Celeste M Nelson
- Department of Molecular Biology, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ 08544, USA
- Department of Chemical and Biological Engineering, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ 08544, USA
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Zhou H, Wu Q, Wei L, Peng S. Paeoniflorin inhibits PDGF‑BB‑induced human airway smooth muscle cell growth and migration. Mol Med Rep 2017; 17:2660-2664. [PMID: 29207148 DOI: 10.3892/mmr.2017.8180] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 03/21/2017] [Indexed: 11/05/2022] Open
Abstract
Abnormal proliferation and migration of airway smooth muscle cells (ASMCs) is important in the progression of asthma. Paeoniflorin (PF), one of the major active ingredients of Paeonia lactiflora, has been reported to exhibit anti‑asthmatic effects. However, the effects of PF in the regulation of platelet‑derived growth factor (PDGF)‑BB‑induced ASMC proliferation and migration remain unknown. The present study was designed to investigate the effects of PF on human ASMCs and the underlying mechanism. The results demonstrated that PF treatment significantly reduced the numbers of live ASMC cells and their PDGF‑BB‑induced migration. PF treatment also suppressed PDGF‑BB‑induced α‑smooth muscle actin expression in ASMCs. Furthermore, pretreatment with PF reduced PDGF‑BB‑induced phosphorylation of phosphoinositide 3‑kinase (PI3K) and AKT serine/threonine kinase 1 (Akt) in ASMCs. In conclusion, the present study demonstrated for the first time that PF inhibited ASMC growth and migration induced by PDGF‑BB, and that this effect may be partly due to inhibition of the PI3K/Akt signaling pathway. The results provide novel information regarding the role of PF as a potential therapeutic agent for the treatment of asthma.
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Affiliation(s)
- Hong Zhou
- Graduate School of Tianjin Medical University, Tianjin 300070, P.R. China
| | - Qi Wu
- Department of Respiration, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Luqing Wei
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Logistics University of Chinese People's Armed Police Force, Tianjin 300162, P.R. China
| | - Shouchun Peng
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Logistics University of Chinese People's Armed Police Force, Tianjin 300162, P.R. China
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Airway remodeling in asthma: what really matters. Cell Tissue Res 2017; 367:551-569. [PMID: 28190087 PMCID: PMC5320023 DOI: 10.1007/s00441-016-2566-8] [Citation(s) in RCA: 253] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/21/2016] [Indexed: 12/21/2022]
Abstract
Airway remodeling is generally quite broadly defined as any change in composition, distribution, thickness, mass or volume and/or number of structural components observed in the airway wall of patients relative to healthy individuals. However, two types of airway remodeling should be distinguished more clearly: (1) physiological airway remodeling, which encompasses structural changes that occur regularly during normal lung development and growth leading to a normal mature airway wall or as an acute and transient response to injury and/or inflammation, which ultimately results in restoration of a normal airway structures; and (2) pathological airway remodeling, which comprises those structural alterations that occur as a result of either disturbed lung development or as a response to chronic injury and/or inflammation leading to persistently altered airway wall structures and function. This review will address a few major aspects: (1) what are reliable quantitative approaches to assess airway remodeling? (2) Are there any indications supporting the notion that airway remodeling can occur as a primary event, i.e., before any inflammatory process was initiated? (3) What is known about airway remodeling being a secondary event to inflammation? And (4), what can we learn from the different animal models ranging from invertebrate to primate models in the study of airway remodeling? Future studies are required addressing particularly pheno-/endotype-specific aspects of airway remodeling using both endotype-specific animal models and “endotyped” human asthmatics. Hopefully, novel in vivo imaging techniques will be further advanced to allow monitoring development, growth and inflammation of the airways already at a very early stage in life.
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7
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Chen H, Xia Q, Feng X, Cao F, Yu H, Song Y, Ni X. Effect of P2X4R on airway inflammation and airway remodeling in allergic airway challenge in mice. Mol Med Rep 2015; 13:697-704. [PMID: 26648454 PMCID: PMC4686060 DOI: 10.3892/mmr.2015.4622] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 10/29/2015] [Indexed: 11/29/2022] Open
Abstract
P2X4 receptor (P2X4R) is the most widely expressed subtype of the P2XRs in the purinergic receptor family. Adenosine triphosphate (ATP), a ligand for this receptor, has been implicated in the pathogenesis of asthma. ATP-P2X4R signaling is involved in pulmonary vascular remodeling, and in the proliferation and differentiation of airway and alveolar epithelial cell lines. However, the role of P2X4R in asthma remains to be elucidated. This aim of the present study was to investigate the effects of P2X4R in a murine experimental asthma model. The asthmatic model was established by the inhalation of ovalbumin (OVA) in BALB/c mice. The mice were treated with P2X4R-specific agonists and antagonists to investigate the role of this receptor in vivo. Pathological changes in the bronchi and lung tissues were examined using hematoxylin and eosin staining, Masson's trichrome staining and Alcian blue staining. The inflammatory cells in the bronchoalveolar lavage fluid were counted, and the expression levels of P2X4R, α-smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA) were detected using western blotting. In the OVA-challenged mice, inflammation, infiltration, collagen deposition, mucus production, and the expression levels of P2X4R and PCNA were all increased; however, the expression of α-SMA was decreased, compared with the mice in the control group. Whereas treatment with the P2X4R agonist, ATP, enhanced the allergic reaction, treatment with the P2X4R antagonist, 5-BDBD, attenuated the allergic reaction. The results suggested that ATP-P2X4R signaling may not only contribute to airway inflammation, but it may also contribute to airway remodeling in allergic asthma in mice.
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Affiliation(s)
- Hongxia Chen
- Department of Pathology, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Qingqing Xia
- Department of Anatomy, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Xiaoqian Feng
- Department of Pathology, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Fangyuan Cao
- Department of Pathology, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Hang Yu
- Department of Physiology, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Yinli Song
- Department of Pathology, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
| | - Xiuqin Ni
- Department of Anatomy, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319, P.R. China
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Shaifta Y, Irechukwu N, Prieto-Lloret J, MacKay CE, Marchon KA, Ward JPT, Knock GA. Divergent modulation of Rho-kinase and Ca(2+) influx pathways by Src family kinases and focal adhesion kinase in airway smooth muscle. Br J Pharmacol 2015; 172:5265-80. [PMID: 26294392 PMCID: PMC4864488 DOI: 10.1111/bph.13313] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/02/2015] [Accepted: 08/19/2015] [Indexed: 02/06/2023] Open
Abstract
Background and Purpose The importance of tyrosine kinases in airway smooth muscle (ASM) contraction is not fully understood. The aim of this study was to investigate the role of Src‐family kinases (SrcFK) and focal adhesion kinase (FAK) in GPCR‐mediated ASM contraction and associated signalling events. Experimental Approach Contraction was recorded in intact or α‐toxin permeabilized rat bronchioles. Phosphorylation of SrcFK, FAK, myosin light‐chain‐20 (MLC20) and myosin phosphatase targeting subunit‐1 (MYPT‐1) was evaluated in cultured human ASM cells (hASMC). [Ca2+]i was evaluated in Fura‐2 loaded hASMC. Responses to carbachol (CCh) and bradykinin (BK) and the contribution of SrcFK and FAK to these responses were determined. Key Results Contractile responses in intact bronchioles were inhibited by antagonists of SrcFK, FAK and Rho‐kinase, while after α‐toxin permeabilization, they were sensitive to inhibition of SrcFK and Rho‐kinase, but not FAK. CCh and BK increased phosphorylation of MYPT‐1 and MLC20 and auto‐phosphorylation of SrcFK and FAK. MYPT‐1 phosphorylation was sensitive to inhibition of Rho‐kinase and SrcFK, but not FAK. Contraction induced by SR Ca2+ depletion and equivalent [Ca2+]i responses in hASMC were sensitive to inhibition of both SrcFK and FAK, while depolarization‐induced contraction was sensitive to FAK inhibition only. SrcFK auto‐phosphorylation was partially FAK‐dependent, while FAK auto‐phosphorylation was SrcFK‐independent. Conclusions and Implications SrcFK mediates Ca2+‐sensitization in ASM, while SrcFK and FAK together and individually influence multiple Ca2+ influx pathways. Tyrosine phosphorylation is therefore a key upstream signalling event in ASM contraction and may be a viable target for modulating ASM tone in respiratory disease.
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Affiliation(s)
- Yasin Shaifta
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Nneka Irechukwu
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jesus Prieto-Lloret
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Charles E MacKay
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Keisha A Marchon
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jeremy P T Ward
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Greg A Knock
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
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Donovan C, Bailey SR, Tran J, Haitsma G, Ibrahim ZA, Foster SR, Tang MLK, Royce SG, Bourke JE. Rosiglitazone elicits in vitro relaxation in airways and precision cut lung slices from a mouse model of chronic allergic airways disease. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1219-28. [PMID: 26386117 DOI: 10.1152/ajplung.00156.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/04/2015] [Indexed: 12/14/2022] Open
Abstract
Rosiglitazone (RGZ), a peroxisome proliferator-activated receptor-γ (PPARγ) ligand, is a novel dilator of small airways in mouse precision cut lung slices (PCLS). In this study, relaxation to RGZ and β-adrenoceptor agonists were compared in trachea from naïve mice and guinea pigs and trachea and PCLS from a mouse model of chronic allergic airways disease (AAD). Airways were precontracted with methacholine before addition of PPARγ ligands [RGZ, ciglitazone (CGZ), or 15-deoxy-(Δ12,14)-prostaglandin J2 (15-deoxy-PGJ2)] or β-adrenoceptor agonists (isoprenaline and salbutamol). The effects of T0070907 and GW9662 (PPARγ antagonists) or epithelial removal on relaxation were assessed. Changes in force of trachea and lumen area in PCLS were measured using preparations from saline-challenged mice and mice sensitized (days 0 and 14) and challenged with ovalbumin (3 times/wk, 6 wk). RGZ and CGZ elicited complete relaxation with greater efficacy than β-adrenoceptor agonists in mouse airways but not guinea pig trachea, while 15-deoxy-PGJ2 did not mediate bronchodilation. Relaxation to RGZ was not prevented by T0070907 or GW9662 or by epithelial removal. RGZ-induced relaxation was preserved in the trachea and increased in PCLS after ovalbumin-challenge. Although RGZ was less potent than β-adrenoceptor agonists, its effects were additive with salbutamol and isoprenaline and only RGZ maintained potency and full efficacy in maximally contracted airways or after allergen challenge. Acute PPARγ-independent, epithelial-independent airway relaxation to RGZ is resistant to functional antagonism and maintained in both trachea and PCLS from a model of chronic AAD. These novel efficacious actions of RGZ support its therapeutic potential in asthma when responsiveness to β-adrenoceptor agonists is limited.
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Affiliation(s)
- Chantal Donovan
- Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Australia; Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Simon R Bailey
- Faculty of Veterinary Science, University of Melbourne, Parkville, Australia; and
| | - Jenny Tran
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Gertruud Haitsma
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Zaridatul A Ibrahim
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Simon R Foster
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Mimi L K Tang
- Department of Allergy and Immunology, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
| | - Simon G Royce
- Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Australia; Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia; Department of Allergy and Immunology, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
| | - Jane E Bourke
- Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Australia; Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia;
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Koopmans T, Anaparti V, Castro-Piedras I, Yarova P, Irechukwu N, Nelson C, Perez-Zoghbi J, Tan X, Ward JPT, Wright DB. Ca2+ handling and sensitivity in airway smooth muscle: emerging concepts for mechanistic understanding and therapeutic targeting. Pulm Pharmacol Ther 2014; 29:108-20. [PMID: 24831539 DOI: 10.1016/j.pupt.2014.05.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/28/2014] [Accepted: 05/01/2014] [Indexed: 02/01/2023]
Abstract
Free calcium ions within the cytosol serve as a key secondary messenger system for a diverse range of cellular processes. Dysregulation of cytosolic Ca(2+) handling in airway smooth muscle (ASM) has been implicated in asthma, and it has been hypothesised that this leads, at least in part, to associated changes in both the architecture and function of the lung. Significant research is therefore directed towards furthering our understanding of the mechanisms which control ASM cytosolic calcium, in addition to those regulating the sensitivity of its downstream effector targets to calcium. Key aspects of the recent developments in this field were discussed at the 8th Young Investigators' Symposium on Smooth Muscle (2013, Groningen, The Netherlands), and are outlined in this review.
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Affiliation(s)
- T Koopmans
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - V Anaparti
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - I Castro-Piedras
- Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, TX, USA
| | - P Yarova
- Cardiff School of Biosciences, Cardiff University, UK
| | - N Irechukwu
- Division of Asthma, Allergy and Lung Biology, King's College London, UK
| | - C Nelson
- School of Science & Technology, Nottingham Trent University, Nottingham, UK
| | - J Perez-Zoghbi
- Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, TX, USA
| | - X Tan
- Lung Inflammation & Infection Lab, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - J P T Ward
- Division of Asthma, Allergy and Lung Biology, King's College London, UK
| | - D B Wright
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands; Division of Asthma, Allergy and Lung Biology, King's College London, UK.
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Donovan C, Royce SG, Esposito J, Tran J, Ibrahim ZA, Tang MLK, Bailey S, Bourke JE. Differential effects of allergen challenge on large and small airway reactivity in mice. PLoS One 2013; 8:e74101. [PMID: 24040180 PMCID: PMC3765301 DOI: 10.1371/journal.pone.0074101] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 07/30/2013] [Indexed: 01/21/2023] Open
Abstract
The relative contributions of large and small airways to hyperresponsiveness in asthma have yet to be fully assessed. This study used a mouse model of chronic allergic airways disease to induce inflammation and remodelling and determine whether in vivo hyperresponsiveness to methacholine is consistent with in vitro reactivity of trachea and small airways. Balb/C mice were sensitised (days 0, 14) and challenged (3 times/week, 6 weeks) with ovalbumin. Airway reactivity was compared with saline-challenged controls in vivo assessing whole lung resistance, and in vitro measuring the force of tracheal contraction and the magnitude/rate of small airway narrowing within lung slices. Increased airway inflammation, epithelial remodelling and fibrosis were evident following allergen challenge. In vivo hyperresponsiveness to methacholine was maintained in isolated trachea. In contrast, methacholine induced slower narrowing, with reduced potency in small airways compared to controls. In vitro incubation with IL-1/TNFα did not alter reactivity. The hyporesponsiveness to methacholine in small airways within lung slices following chronic ovalbumin challenge was unexpected, given hyperresponsiveness to the same agonist both in vivo and in vitro in tracheal preparations. This finding may reflect the altered interactions of small airways with surrounding parenchymal tissue after allergen challenge to oppose airway narrowing and closure.
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Affiliation(s)
- Chantal Donovan
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Simon G. Royce
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
- Department of Allergy & Immunology, Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - James Esposito
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Jenny Tran
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Zaridatul Aini Ibrahim
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Mimi L. K. Tang
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
- Department of Allergy & Immunology, Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Simon Bailey
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
- Faculty of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
| | - Jane E. Bourke
- Lung Health Research Centre, Department of Pharmacology & Therapeutics, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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12
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Siddiqui S, Novali M, Tsuchiya K, Hirota N, Geller BJ, McGovern TK, Risse PA, Jo T, Zeroual MA, Martin JG. The modulation of large airway smooth muscle phenotype and effects of epidermal growth factor receptor inhibition in the repeatedly allergen-challenged rat. Am J Physiol Lung Cell Mol Physiol 2013; 304:L853-62. [PMID: 23605002 DOI: 10.1152/ajplung.00047.2012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Allergen challenges induce airway hyperresponsiveness (AHR) and increased airway smooth muscle (ASM) mass in the sensitized rat. Whether the remodeled ASM changes its phenotype is uncertain. We examined, in sensitized Brown Norway rats, the effects of multiple ovalbumin (Ova) challenges on ASM remodeling and phenotype and the role of the epidermal growth factor receptor (EGFR) in these processes. Rats were sensitized with Ova and challenged three times at 5-day intervals with phosphate-buffered saline or Ova and pretreated with the EGFR inhibitor AG-1478 (5 mg/kg) or its vehicle dimethyl sulfoxide. Ova challenges increased ASM mass in all-sized airways and in large airway mRNA expression of smooth muscle myosin heavy chain (sm-MHC), assessed by laser capture. Myosin light chain kinase and the fast myosin isoform SM-B mRNA expressions were not affected. Ova induced AHR to methacholine, and, based on the constant-phase model, this was largely attributable to the small airways and lung derecruitment at 48 h that recovered by 1 wk. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor (HB-EGF) were increased in bronchoalveolar lavage fluid at 48 h after Ova exposure. AG-1478 inhibited AHR and prevented ASM growth. Epithelial gene expression of EGFR, HB-EGF, matrix metalloproteinase (MMP)-9, Gro-α, and transforming growth factor-β was unaffected by Ova challenges. We conclude that EGFR drives remodeling of ASM, which results from repeated Ova challenge. Furthermore, the latter results in excessive small airway and, to a lesser degree, large airway narrowing to methacholine, and large airway gene expression of contractile protein is conserved.
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Affiliation(s)
- S Siddiqui
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montreal, Quebec, Canada
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13
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Ning Y, Huang H, Dong Y, Sun Q, Zhang W, Xu W, Li Q. 5-Aza-2'-deoxycytidine inhibited PDGF-induced rat airway smooth muscle cell phenotypic switching. Arch Toxicol 2013; 87:871-81. [PMID: 23423710 DOI: 10.1007/s00204-012-1008-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 12/20/2012] [Indexed: 11/30/2022]
Abstract
Airway smooth muscle (ASM) cell phenotypic switching played an important role in airway remodeling in asthma. In vitro platelet-derived growth factor (PDGF) induced ASM cell phenotypic switching from a mature to pro-remodeling phenotype, but the mechanism remained incompletely understood. This study was to explore the effect of DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (Aza-CdR) on PDGF-induced rat ASM cell phenotypic switching and biological behaviors. Rat airway smooth muscle (RASM) cells were obtained by primary explant techniques. Western blot, 3-dimensional gel contraction, transwell and wound healing assay, and MTT were applied to detect cell phenotypic switching, contractility, migration and proliferation, respectively. Cytoskeleton rearrangement was observed by immunofluorescence. Results showed Aza-CdR inhibited PDGF-induced down-regulation of contractile markers in RASM cells and increased cell contractility. Aza-CdR inhibited PDGF-induced RASM cell migration by abrogating cell morphology change and cytoskeletal reorganization and attenuated the effect of PDGF on proliferating cell nuclear antigen expression and cell cycle progression, ultimately cell proliferation. PDGF-induced DNA methyltransferase 1 (DNMT1) expression was mediated by activation of PI3K/Akt and ERK signaling in RASM cells. Selective depletion of DNMT1 protein by Aza-CdR inhibited PDGF-induced RASM cell phenotypic switching, revealing DNMT1-mediated DNA methylation was implicated in asthmatic ASM remodeling. We proposed for the first time that DNMT1 played a key role in PDGF-induced RASM cell phenotypic switching and Aza-CdR is promising in intervening ASM remodeling in asthma. Although study of abnormal DNA methylation in PDGF-stimulated ASM cells is in its infancy, this work contributes to providing new insights into the mechanism of ASM remodeling and may be helpful for developing effective treatments for airway remodeling in asthma.
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Affiliation(s)
- Yunye Ning
- Department of Respiratory Medicine, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Yangpu District, Shanghai, 200433, People's Republic of China
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14
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Functional phenotype of airway myocytes from asthmatic airways. Pulm Pharmacol Ther 2012; 26:95-104. [PMID: 22921313 DOI: 10.1016/j.pupt.2012.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 08/08/2012] [Accepted: 08/08/2012] [Indexed: 11/23/2022]
Abstract
In asthma, the airway smooth muscle (ASM) cell plays a central role in disease pathogenesis through cellular changes which may impact on its microenvironment and alter ASM response and function. The answer to the long debated question of what makes a 'healthy' ASM cell become 'asthmatic' still remains speculative. What is known of an 'asthmatic' ASM cell, is its ability to contribute to the hallmarks of asthma such as bronchoconstriction (contractile phenotype), inflammation (synthetic phenotype) and ASM hyperplasia (proliferative phenotype). The phenotype of healthy or diseased ASM cells or tissue for the most part is determined by expression of key phenotypic markers. ASM is commonly accepted to have different phenotypes: the contractile (differentiated) state versus the synthetic (dedifferentiated) state (with the capacity to synthesize mediators, proliferate and migrate). There is now accumulating evidence that the synthetic functions of ASM in culture derived from asthmatic and non-asthmatic donors differ. Some of these differences include an altered profile and increased production of extracellular matrix proteins, pro-inflammatory mediators and adhesion receptors, collectively suggesting that ASM cells from asthmatic subjects have the capacity to alter their environment, actively participate in repair processes and functionally respond to changes in their microenvironment.
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15
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PPARγ Ligands Regulate Noncontractile and Contractile Functions of Airway Smooth Muscle: Implications for Asthma Therapy. PPAR Res 2012; 2012:809164. [PMID: 22966222 PMCID: PMC3431171 DOI: 10.1155/2012/809164] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 06/12/2012] [Indexed: 01/22/2023] Open
Abstract
In asthma, the increase in airway smooth muscle (ASM) can contribute to inflammation, airway wall remodeling and airway hyperresponsiveness (AHR). Targetting peroxisome proliferator-activated receptor γ (PPARγ), a receptor upregulated in ASM in asthmatic airways, may provide a novel approach to regulate these contributions. This review summarises experimental evidence that PPARγ ligands, such as rosiglitazone (RGZ) and pioglitazone (PGZ), inhibit proliferation and inflammatory cytokine production from ASM in vitro. In addition, inhaled administration of these ligands reduces inflammatory cell infiltration and airway remodelling in mouse models of allergen-induced airways disease. PPARγ ligands can also regulate ASM contractility, with acute treatment eliciting relaxation of mouse trachea in vitro through a PPARγ-independent mechanism. Chronic treatment can protect against the loss of bronchodilator sensitivity to β2-adrenoceptor agonists and inhibit the development of AHR associated with exposure to nicotine in utero or following allergen challenge. Of particular interest, a small clinical trial has shown that oral RGZ treatment improves lung function in smokers with asthma, a group that is generally unresponsive to conventional steroid treatment. These combined findings support further investigation of the potential for PPARγ agonists to target the noncontractile and contractile functions of ASM to improve outcomes for patients with poorly controlled asthma.
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Karmouty-Quintana H, Siddiqui S, Hassan M, Tsuchiya K, Risse PA, Xicota-Vila L, Marti-Solano M, Martin JG. Treatment with a sphingosine-1-phosphate analog inhibits airway remodeling following repeated allergen exposure. Am J Physiol Lung Cell Mol Physiol 2012; 302:L736-45. [PMID: 22287614 DOI: 10.1152/ajplung.00050.2011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sphingosine-1-phosphate (S1P) is an immunomodulatory lipid mediator that plays an important role in lymphocyte trafficking. Elevated levels of S1P are found in bronchoalveolar lavage (BAL) fluid of patients with asthma; however, its role in disease is not known. FTY720, a synthetic analog of S1P, has been shown to abrogate allergic inflammation and airway hyperresponsiveness following acute allergen challenge. However, its effects on asthmatic airway remodeling induced by repeated allergen exposure are unknown. Ovalbumin (OVA)-sensitized rats were challenged on days 14, 19, and 24 after sensitization. FTY720 or vehicle (PBS) therapy was administered 1 h prior to each challenge. BAL fluid and quantitative histological analysis were performed 48 h after the last challenge. FTY720 inhibited OVA-induced features of airway remodeling including increased airway smooth muscle mass and bronchial neovascularization, without affecting lymphocyte numbers in secondary lymphoid organs. Furthermore, CD3+ cells adjacent to airway smooth muscle bundles were increased in OVA-challenged rats but the increase was inhibited by FTY720. There was an expansion of bronchus-associated lymphoid tissue following FTY720 treatment of OVA-challenged animals. Real-time quantitative PCR revealed that Th2-associated transcription factors were inhibited following FTY720 therapy. Airway remodeling is a cardinal feature of severe asthma. These results demonstrate that allergen-driven airway remodeling can be inhibited by FTY720, offering potential new therapies for the treatment of severe asthma.
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Verbout NG, Jacoby DB. Muscarinic receptor agonists and antagonists: effects on inflammation and immunity. Handb Exp Pharmacol 2012:403-27. [PMID: 22222708 DOI: 10.1007/978-3-642-23274-9_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this chapter, we will review what is known about muscarinic regulation of immune cells and the contribution of immune cell muscarinic receptors to inflammatory disease and immunity. In particular, immune cell expression of cholinergic machinery, muscarinic receptor subtypes and functional consequences of agonist stimulation will be reviewed. Lastly, this chapter will discuss the potential therapeutic effects of selective antagonists on immune cell function and inflammatory disease in recent animal studies and human clinical trials.
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Affiliation(s)
- Norah G Verbout
- School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
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18
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Animal models of chronic experimental asthma - strategies for the identification of new therapeutic targets. J Occup Med Toxicol 2011; 3 Suppl 1:S4. [PMID: 18315835 PMCID: PMC2259398 DOI: 10.1186/1745-6673-3-s1-s4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Over the last decade mouse models of experimental asthma proved to be a valuable tool for the investigation of mechanisms that underlie acute allergic airway inflammation and development of airway hyperresponsiveness, two of the hallmarks of human asthma. Nevertheless, these acute models fail to reflect the aspects of this chronic disease because they do not represent any signs of chronicity and airway remodelling as it is defined by subepithelial fibrosis, goblet cell hyperplasia and airway smooth muscle cell hypertrophy. Recent mouse models were successful in overcoming these limitations by using chronic allergen-challenges. These new models of chronic experimental asthma now proved as a novel tool to examine the complex interaction of infiltrating inflammatory cells and structural cells such as fibroblasts and smooth muscle cells that ultimately leads to airway remodelling and stable airflow limitation. Recent studies clearly demonstrated that T helper 2 (TH2) cells and their typical cytokines play a critical role not only in airway inflammation but also in the development of airway remodelling. Since the transcription factor GATA-3 is essential for TH2 cell development and the production of several TH2 type cytokines this intracellular molecule represents a new promising target for therapeutic intervention in asthma that might even effect airway remodelling.
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19
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Risse PA, Jo T, Suarez F, Hirota N, Tolloczko B, Ferraro P, Grutter P, Martin JG. Interleukin-13 inhibits proliferation and enhances contractility of human airway smooth muscle cells without change in contractile phenotype. Am J Physiol Lung Cell Mol Physiol 2011; 300:L958-66. [PMID: 21460123 DOI: 10.1152/ajplung.00247.2010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
IL-13 is an important mediator of allergen-induced airway hyperresponsiveness. This Th2 cytokine, produced by activated T cells, mast cells, and basophils, has been described to mediate a part of its effects independently of inflammation through a direct modulation of the airway smooth muscle (ASM). Previous studies demonstrated that IL-13 induces hyperresponsiveness in vivo and enhances calcium signaling in response to contractile agonists in vitro. We hypothesized that IL-13 drives human ASM cells (ASMC) to a procontractile phenotype. We evaluated ASM phenotype through the ability of the cell to proliferate, to contract, and to express contractile protein in response to IL-13. We found that IL-13 inhibits human ASMC proliferation (expression of Ki67 and bromodeoxyuridine incorporation) in response to serum, increasing the number of cells in G0/G1 phase and decreasing the number of cells in G2/M phases of the cell cycle. IL-13-induced inhibition of proliferation was not dependent on signal transducer and activator of transcription-6 but was IL-13Rα2 receptor dependent and associated with a decrease of Kruppel-like factor 5 expression. In parallel, IL-13 increased calcium signaling and the stiffening of human ASMC in response to 1 μM histamine, whereas the stiffening response to 30 mM KCl was unchanged. However, Western blot analysis showed unchanged levels of calponin, smooth muscle α-actin, vinculin, and myosin. We conclude that IL-13 inhibits proliferation via the IL-13Rα2 receptor and induces hypercontractility of human ASMC without change of the phenotypic markers of contractility.
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Affiliation(s)
- Paul-André Risse
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montréal, Canada
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20
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Siddiqui S, Jo T, Tamaoka M, Shalaby KH, Ghezzo H, Bernabeu M, Martin JG. Sites of allergic airway smooth muscle remodeling and hyperresponsiveness are not associated in the rat. J Appl Physiol (1985) 2010; 109:1170-8. [PMID: 20651225 DOI: 10.1152/japplphysiol.01168.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cause-and-effect relationship between airway smooth muscle (ASM) remodeling and airway hyperresponsiveness (AHR) following allergen challenge is not well established. Using a rat model of allergen-induced ASM remodeling we explored the relationship between the site of ASM remodeling and AHR. Brown Norway rats, sensitized and challenged (3 times at 5-day intervals) with ovalbumin, were intranasally administered 0.1 mg/kg budesonide 24 and 1 h before challenge. Airway responses to aerosolized methacholine were assessed 48 h or 1 wk after three challenges. Airways were stained and analyzed for total airway wall area, area of smooth muscle-specific α-actin, and goblet cell hyperplasia, and the constant-phase model was used to resolve the changes in respiratory system mechanics into large airway and peripheral lung responses. After three ovalbumin challenges, there was a significant increase in ASM area and in the total wall area in all sized airways as well as an increase in goblet cells in the central airways. Budesonide inhibited ASM growth and central airway goblet cell hyperplasia following ovalbumin challenges. Budesonide also inhibited small but not large airway total wall area. AHR was attributable to excessive responses of the small airways, whereas responsiveness of the large airways was unchanged. Budesonide did not inhibit AHR after repeated challenge. We conclude that ASM remodeling induced by repeated allergen challenges involves the entire bronchial tree, whereas AHR reflects alterations in the lung periphery. Prevention of ASM remodeling by corticosteroid does not abrogate AHR.
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Affiliation(s)
- Sana Siddiqui
- Meakins Christie Laboratories, Department of Medicine, McGill University, Montreal, Quebec, Canada
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21
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Ramos-Barbón D, Fraga-Iriso R, Brienza NS, Montero-Martínez C, Verea-Hernando H, Olivenstein R, Lemiere C, Ernst P, Hamid QA, Martin JG. T Cells localize with proliferating smooth muscle alpha-actin+ cell compartments in asthma. Am J Respir Crit Care Med 2010; 182:317-24. [PMID: 20395563 DOI: 10.1164/rccm.200905-0745oc] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Airway remodeling in asthma comprises increased airway smooth muscle (ASM), an alteration linked to airway hyperresponsiveness and disease severity. Experimental studies showed that T cells adhere to ASM through vascular cell adhesion molecule-1 (VCAM-1) and drive ASM growth through direct contact between the T cells and smooth muscle alpha-actin (alpha-SMA)(+) cells. OBJECTIVES To support the hypothesis of a T-cell/alpha-SMA(+) cell contact mechanism of ASM remodeling in asthma, using bronchial biopsies. METHODS We performed quantitative morphology on T cells, proliferating cell nuclear antigen (PCNA), alpha-SMA, and VCAM-1 on biopsies from subjects with moderate and severe asthma and healthy control subjects. MEASUREMENTS AND MAIN RESULTS We demonstrate ASM cell proliferation and infiltration by T cells in proportion to severity in the subjects with asthma. T cells localized with alpha-SMA(+)PCNA(+) cells, suggesting direct intercellular contact and a relationship with alpha-SMA(+) cell proliferation. Furthermore, the subjects with asthma developed a proliferating compartment of subepithelial alpha-SMA(+), nonorganized airway contractile elements (NOACE), suggesting a phenotype gradient from undifferentiated cells to smooth muscle-like cells. T-cell juxtaposition events were also observed in this compartment and correlated to its mass. The subjects with asthma showed VCAM-1 expression in postcapillary venules and clusters of VCAM-1 immunoreactivity in ASM and NOACE, consistent with a role of VCAM-1 in T-cell/alpha-SMA(+) cell interaction. CONCLUSIONS T cells may induce alpha-SMA(+) cell proliferation through direct intercellular contact. NOACE may in part contribute to ASM growth through differentiation and translocation of alpha-SMA(+) cells. The findings support the role of the T cell in ASM remodeling in asthma.
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22
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Labonté I, Hassan M, Risse PA, Tsuchiya K, Laviolette M, Lauzon AM, Martin JG. The effects of repeated allergen challenge on airway smooth muscle structural and molecular remodeling in a rat model of allergic asthma. Am J Physiol Lung Cell Mol Physiol 2009; 297:L698-705. [PMID: 19648284 DOI: 10.1152/ajplung.00142.2009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of remodeling of airway smooth muscle (SM) by hyperplasia on airway SM contractility in vivo are poorly explored. The aim of this study was to investigate the relationship between allergen-induced airway SM hyperplasia and its contractile phenotype. Brown Norway rats were sensitized with ovalbumin (OVA) or saline on day 0 and then either OVA-challenged once on day 14 and killed 24 h later or OVA-challenged 3 times (on days 14, 19, and 24) and killed 2 or 7 days later. Changes in SM mass, expression of total myosin, SM myosin heavy chain fast isoform (SM-B) and myosin light chain kinase (MLCK), tracheal contractions ex vivo, and airway responsiveness to methacholine (MCh) in vivo were assessed. One day after a single OVA challenge, the number of SM cells positive for PCNA was greater than for control animals, whereas the SM mass, contractile phenotype, and tracheal contractility were unchanged. Two days after three challenges, SM mass and PCNA immunoreactive cells were increased (3- and 10-fold, respectively; P < 0.05), but airway responsiveness to MCh was unaffected. Lower expression in total myosin, SM-B, and MLCK was observed at the mRNA level (P < 0.05), and total myosin and MLCK expression were lower at the protein level (P < 0.05) after normalization for SM mass. Normalized tracheal SM force generation was also significantly lower 2 days after repeated challenges (P < 0.05). Seven days after repeated challenges, features of remodeling were restored toward control levels. Allergen-induced hyperplasia of SM cells was associated with a loss of contractile phenotype, which was offset by the increase in mass.
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Affiliation(s)
- Isabelle Labonté
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montreal, QC, Canada H2X 2P2
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23
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Allen JE, Bischof RJ, Sucie Chang HY, Hirota JA, Hirst SJ, Inman MD, Mitzner W, Sutherland TE. Animal models of airway inflammation and airway smooth muscle remodelling in asthma. Pulm Pharmacol Ther 2009; 22:455-65. [PMID: 19393759 DOI: 10.1016/j.pupt.2009.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 12/28/2008] [Accepted: 04/14/2009] [Indexed: 10/24/2022]
Abstract
Asthma is a complex disease that involves chronic inflammation and subsequent decline in airway function. The widespread use of animal models has greatly contributed to our understanding of the cellular and molecular pathways underlying human allergic asthma. Animal models of allergic asthma include smaller animal models which offer 'ease of use' and availability of reagents, and larger animal models that may be used to address aspects of allergic airways disease not possible in humans or smaller animal models. This review examines the application and suitability of various animal models for studying mechanisms of airway inflammation and tissue remodelling in allergic asthma, with a specific focus on airway smooth muscle.
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Affiliation(s)
- Judith E Allen
- Ashworth Laboratory, Institute of Infection and Immunology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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24
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Ceresa CC, Knox AJ, Johnson SR. Use of a three-dimensional cell culture model to study airway smooth muscle-mast cell interactions in airway remodeling. Am J Physiol Lung Cell Mol Physiol 2009; 296:L1059-66. [PMID: 19346431 DOI: 10.1152/ajplung.90445.2008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased airway smooth muscle (ASM) mass and infiltration by mast cells are key features of airway remodeling in asthma. We describe a model to investigate the relationship between ASM, the extracellular matrix, mast cells, and airway remodeling. ASM cells were cultured in a three-dimensional (3-D) collagen I gel (3-D culture) alone or with mast cells. Immunocytochemistry and Western blotting of ASM in 3-D cultures revealed a spindle-shaped morphology and significantly lower alpha-smooth muscle actin and vimentin expression than in ASM cultured in monolayers on collagen type I or plastic (2-D culture). In 3-D cultures, basal ASM proliferation, examined by Ki67 immunocytochemistry, was reduced to 33 +/- 7% (P < 0.05) of that in 2-D cultures. The presence of mast cells in cocultures increased ASM proliferation by 1.8-fold (P < 0.05). Gelatin zymography revealed more active matrix metalloproteinase (MMP)-2 in 3-D than in 2-D culture supernatants over 7 days. Functional MMP activity was examined by gel contraction. The spontaneous gel contraction over 7 days was significantly inhibited by the MMP inhibitor ilomastat. Mast cell coculture enhanced ASM gel contraction by 22 +/- 16% (not significant). Our model shows that ASM has different morphology, with lower contractile protein expression and basal proliferation in 3-D culture. Compared with standard techniques, ASM synthetic function, as shown by MMP production and activity, is sustained over longer periods. The presence of mast cells in the 3-D model enhanced ASM proliferation and MMP production. Airway remodeling in asthma may be more accurately modeled by our system than by standard culture systems.
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Affiliation(s)
- Claudia C Ceresa
- Divisions of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, United Kingdom
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25
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Hirota JA, Nguyen TTB, Schaafsma D, Sharma P, Tran T. Airway smooth muscle in asthma: phenotype plasticity and function. Pulm Pharmacol Ther 2008; 22:370-8. [PMID: 19114115 DOI: 10.1016/j.pupt.2008.12.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 11/14/2008] [Accepted: 12/10/2008] [Indexed: 10/24/2022]
Abstract
Clinical asthma is characterized by reversible airway obstruction which is commonly due to an exaggerated airway narrowing referred to as airway hyperresponsiveness (AHR). Although debate exists on the complex etiology of AHR, it is clear that airway smooth muscle (ASM) mediated airway narrowing is a major contributor to airway dysfunction. More importantly, it is now appreciated that smooth muscle is far from being a simple cell with only contractile ability properties. Rather, it is more versatile with the capacity to exhibit numerous cellular functions as it adapts to the microenvironment to which it is exposed. The emerging ability of individual smooth muscle cells to undergo changes in their phenotype (phenotype plasticity) and function (functional plasticity) in response to physiological and pathological cues is an important and active area of research. This article provides a brief review of the current knowledge and emerging concepts in the field of ASM phenotype and function both under healthy and asthmatic conditions.
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Affiliation(s)
- Jeremy A Hirota
- Firestone Institute for Respiratory Health, McMaster University, Ontario, Canada
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26
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Siddiqui S, Martin JG. Structural aspects of airway remodeling in asthma. Curr Allergy Asthma Rep 2008; 8:540-7. [PMID: 18940147 DOI: 10.1007/s11882-008-0098-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Airway remodeling in asthma is a complex process that involves structural changes in virtually all tissues of the airway wall. The histologic changes to the airways consist of epithelial proliferation and goblet cell differentiation, subepithelial fibrosis, airway smooth muscle (ASM) growth, angiogenesis, matrix protein deposition, gland hyperplasia and hypertrophy, and nerve proliferation. Cytokines, chemokines, and growth factors from inflammatory cells and structural cells contribute to remodeling. There are complex interactions among the various signaling pathways involving matrix metalloproteinases that are required for growth factor release. The physiologic consequences of remodeling are airway hyperresponsiveness from ASM growth and mucus hypersecretion from gland and goblet cell hyperplasia. Airway stiffening is a probable contributor to airway hyperresponsiveness through attenuation of the transmission of potently bronchodilating cyclical stress to the ASM during breathing. The epidermal growth factor receptor's role in remodeling and its interaction with other potential causes of remodeling are discussed.
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Affiliation(s)
- Sana Siddiqui
- Meakins Christie Laboratories, McGill University, 3626 St. Urbain Street, Montreal, Quebec H2X 2P2, Canada
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Lantz RC, Chau B, Sarihan P, Witten ML, Pivniouk VI, Chen GJ. In utero and postnatal exposure to arsenic alters pulmonary structure and function. Toxicol Appl Pharmacol 2008; 235:105-13. [PMID: 19095001 DOI: 10.1016/j.taap.2008.11.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/07/2008] [Accepted: 11/17/2008] [Indexed: 10/21/2022]
Abstract
In addition to cancer endpoints, arsenic exposures can also lead to non-cancerous chronic lung disease. Exposures during sensitive developmental time points can contribute to the adult disease. Using a mouse model, in utero and early postnatal exposures to arsenic (100 ppb or less in drinking water) were found to alter airway reactivity to methacholine challenge in 28 day old pups. Removal of mice from arsenic exposure 28 days after birth did not reverse the alterations in sensitivity to methacholine. In addition, adult mice exposed to similar levels of arsenic in drinking water did not show alterations. Therefore, alterations in airway reactivity were irreversible and specific to exposures during lung development. These functional changes correlated with protein and gene expression changes as well as morphological structural changes around the airways. Arsenic increased the whole lung levels of smooth muscle actin in a dose dependent manner. The level of smooth muscle mass around airways was increased with arsenic exposure, especially around airways smaller than 100 microm in diameter. This increase in smooth muscle was associated with alterations in extracellular matrix (collagen, elastin) expression. This model system demonstrates that in utero and postnatal exposure to environmentally relevant levels of arsenic can irreversibly alter pulmonary structure and function in the adults.
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Affiliation(s)
- R Clark Lantz
- Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85724, USA.
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Bentley JK, Deng H, Linn MJ, Lei J, Dokshin GA, Fingar DC, Bitar KN, Henderson WR, Hershenson MB. Airway smooth muscle hyperplasia and hypertrophy correlate with glycogen synthase kinase-3(beta) phosphorylation in a mouse model of asthma. Am J Physiol Lung Cell Mol Physiol 2008; 296:L176-84. [PMID: 19011050 DOI: 10.1152/ajplung.90376.2008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased airway smooth muscle (ASM) mass, a characteristic finding in asthma, may be caused by hyperplasia or hypertrophy. Cell growth requires increased translation of contractile apparatus mRNA, which is controlled, in part, by glycogen synthase kinase (GSK)-3beta, a constitutively active kinase that inhibits eukaryotic initiation factor-2 activity and binding of methionyl tRNA to the ribosome. Phosphorylation of GSK-3beta inactivates it, enhancing translation. We sought to quantify the contributions of hyperplasia and hypertrophy to increased ASM mass in ovalbumin (OVA)-sensitized and -challenged BALB/c mice and the role of GSK-3beta in this process. Immunofluorescent probes, confocal microscopy, and stereological methods were used to analyze the number and volume of cells expressing alpha-smooth muscle actin and phospho-Ser(9) GSK-3beta (pGSK). OVA treatment caused a 3-fold increase in ASM fractional unit volume or volume density (Vv) (PBS, 0.006 +/- 0.0003; OVA, 0.014 +/- 0.001), a 1.5-fold increase in ASM number per unit volume (Nv), and a 59% increase in volume per cell (Vv/Nv) (PBS, 824 +/- 76 microm(3); OVA, 1,310 +/- 183 mum(3)). In OVA-treated mice, there was a 12-fold increase in the Vv of pGSK (+) ASM, a 5-fold increase in the Nv of pGSK (+) ASM, and a 1.6-fold increase in Vv/Nv. Lung homogenates from OVA-treated mice showed increased GSK-3beta phosphorylation and lower GSK-3beta activity. Both hyperplasia and hypertrophy are responsible for increased ASM mass in OVA-treated mice. Phosphorylation and inactivation of GSK-3beta are associated with ASM hypertrophy, suggesting that this kinase may play a role in asthmatic airway remodeling.
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Affiliation(s)
- J Kelley Bentley
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
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Rho-kinase and contractile apparatus proteins in murine airway hyperresponsiveness. ACTA ACUST UNITED AC 2008; 60:9-15. [PMID: 18434112 DOI: 10.1016/j.etp.2008.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Accepted: 03/07/2008] [Indexed: 11/23/2022]
Abstract
Airway hyperresponsiveness (AHR) is a hallmark of bronchial asthma. Increased expression of smooth muscle contractile proteins or increased responsiveness of the contractile apparatus due to RhoA/Rho-kinase activation may contribute to AHR. BALB/c mice developed AHR following systemic sensitization by intraperitoneal injections of 20 microg ovalbumin (OVA) in presence of 2mg Al(OH)(3) on days 1 and 14, and airway challenge by 1% OVA-inhalation for 20 min each on days 28, 29 and 30. As assessed by Western blot, protein expression of RhoA, MLC (myosin light chain) and smMLCK (smooth muscle myosin light chain kinase) was increased in lungs of OVA/OVA-animals with AHR, as well as in lungs of OVA-sensitized and sham-challenged animals (OVA/PBS) without AHR, compared with lungs of PBS/PBS-animals. Pretreatment with the specific Rho-kinase inhibitor Y-27632 reduced MLC-phosphorylation and AHR. Contribution of Rho-kinase to bronchoconstriction was increased in lungs of OVA/OVA-animals compared with OVA/PBS- and PBS/PBS-animals, respectively. Furthermore, bronchoconstriction following MCh stimulation was significantly reduced after Y-27632 application. In conclusion, systemic allergen-sensitization increased pulmonary expression of proteins involved in smooth muscle contraction, which may contribute to development of AHR. However, this observation was independent from local allergen challenge, suggesting that additional cofactors may be required for the activation of Rho-kinase and thereby the induction of AHR. Rho-kinase may play an important role in murine AHR, and the bronchodilating action of Rho-kinase inhibition may offer a new therapeutic perspective in obstructive airway disease.
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Expression of smooth muscle and extracellular matrix proteins in relation to airway function in asthma. J Allergy Clin Immunol 2008; 121:1196-202. [PMID: 18405955 DOI: 10.1016/j.jaci.2008.02.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 01/03/2008] [Accepted: 02/14/2008] [Indexed: 11/23/2022]
Abstract
BACKGROUND Smooth muscle content is increased within the airway wall in patients with asthma and is likely to play a role in airway hyperresponsiveness. However, smooth muscle cells express several contractile and structural proteins, and each of these proteins may influence airway function distinctly. OBJECTIVE We examined the expression of contractile and structural proteins of smooth muscle cells, as well as extracellular matrix proteins, in bronchial biopsies of patients with asthma, and related these to lung function, airway hyperresponsiveness, and responses to deep inspiration. METHODS Thirteen patients with asthma (mild persistent, atopic, nonsmoking) participated in this cross-sectional study. FEV(1)% predicted, PC(20) methacholine, and resistance of the respiratory system by the forced oscillation technique during tidal breathing and deep breath were measured. Within 1 week, a bronchoscopy was performed to obtain 6 bronchial biopsies that were immunohistochemically stained for alpha-SM-actin, desmin, myosin light chain kinase (MLCK), myosin, calponin, vimentin, elastin, type III collagen, and fibronectin. The level of expression was determined by automated densitometry. RESULTS PC(20) methacholine was inversely related to the expression of alpha-smooth muscle actin (r = -0.62), desmin (r = -0.56), and elastin (r = -0.78). In addition, FEV(1)% predicted was positively related and deep inspiration-induced bronchodilation inversely related to desmin (r = -0.60), MLCK (r = -0.60), and calponin (r = -0.54) expression. CONCLUSION Airway hyperresponsiveness, FEV(1)% predicted, and airway responses to deep inspiration are associated with selective expression of airway smooth muscle proteins and components of the extracellular matrix.
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Airway smooth muscle growth in asthma: proliferation, hypertrophy, and migration. Ann Am Thorac Soc 2008; 5:89-96. [PMID: 18094090 DOI: 10.1513/pats.200705-063vs] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Increased airway smooth muscle mass is present in fatal and non-fatal asthma. However, little information is available regarding the cellular mechanism (i.e., hyperplasia vs. hypertrophy). Even less information exists regarding the functional consequences of airway smooth muscle remodeling. It would appear that increased airway smooth muscle mass would tend to increase airway narrowing and airflow obstruction. However, the precise effects of increased airway smooth muscle mass on airway narrowing are not known. This review will consider the evidence for airway smooth muscle cell proliferation and hypertrophy in asthma, potential functional effects, and biochemical mechanisms.
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Xie M, Liu XS, Xu YJ, Zhang ZX, Bai J, Ni W, Chen SX. ERK1/2 signaling pathway modulates the airway smooth muscle cell phenotype in the rat model of chronic asthma. Respiration 2007; 74:680-90. [PMID: 17890845 DOI: 10.1159/000108783] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Accepted: 04/23/2007] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND It has been demonstrated that the phenotypic modulation of airway smooth muscle cells (ASMCs) is important to the pathogenesis of airway remodeling in chronic asthma. The extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway is one of the most important transduction pathways involved in the process of asthma; however, its role in the phenotypic transition of ASMCs remains unclear. OBJECTIVES To examine the role of ERK1/2 in the phenotypic modulation of ASMCs in the rat model of chronic asthma. METHODS Bronchial smooth muscle strips were cultured in vitro in the presence of the ERK1/2 agonist epidermal growth factor or/and the MEK inhibitor PD98059. The phenotype of ASMCs was determined by observing these cells under an electron microscope and analyzing expression of phenotypic markers (smooth muscle alpha-actin for the contractile phenotype and osteopontin for the synthetic) by using Western blot and reverse-transcriptase polymerase chain reaction, respectively. RESULTS The phenotype of the ASMCs from the chronic asthmatic rats changed from the contractile type to the synthetic type with synthetic organelles abundantly gathered around the nucleus and altered expression of phenotypic markers. ERK1/2 was strongly expressed in the ASMCs of the chronic asthmatic rats and its activation by epidermal growth factor excessively promoted the synthetic function of ASMCs; the MEK inhibitor PD98059, however, reversed this phenotypic change in the ASMCs. CONCLUSIONS Our results reveal a key role of the ERK1/2 signaling pathway in the phenotypic modulation of ASMCs in chronic asthmatic rats, indicating that specific inhibition of ERK1/2 in ASMCs may be therapeutically valuable in the control of airway remodeling in chronic asthma.
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Affiliation(s)
- Min Xie
- Department of Respiratory Medicine, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Southam DS, Ellis R, Wattie J, Inman MD. Components of airway hyperresponsiveness and their associations with inflammation and remodeling in mice. J Allergy Clin Immunol 2007; 119:848-54. [PMID: 17321577 DOI: 10.1016/j.jaci.2006.12.623] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Revised: 12/03/2006] [Accepted: 12/11/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND Pathologic changes, including inflammation and remodeling, occur in the asthmatic airway. However, their relative contribution to the components of airway hyperresponsiveness (AHR) remains unclear. OBJECTIVE Attempting to delineate AHR into discrete immune-mediated and structural remodeling components, we performed a detailed time course of the development, progression, and persistence of maximal respiratory system resistance, airway reactivity, and airway sensitivity. METHODS Mice exposed to increasing durations of persistent allergen were assessed for airway function, morphometry, and inflammation. RESULTS Allergen exposure resulted in increases for all indices of AHR that persisted for at least 4 weeks after chronic allergen exposure (P < .01 for all values). Early increases in AHR were associated with increases in immune-mediated events, including airway eosinophils (P < .01), whereas sustained AHR was associated with structural remodeling events. Increased maximal respiratory system resistance, evident by 6 weeks postallergen and persisting for at least 4 weeks after 8 weeks of chronic exposure, was associated with an increase in collagen deposition (P < .01). Increased airway reactivity and sensitivity, each evident by 1 week after allergen and persisting for at least 4 weeks after 8 weeks of chronic exposure, were associated with an increase in airway smooth muscle area (P < .01). CONCLUSION Our novel observation of distinct temporal relationships in the development, progression, and persistence of the individual indices of AHR supports our hypothesis that multiple underlying factors contribute to airway dysfunction. CLINICAL IMPLICATIONS These findings illustrate the importance of clearly addressing specific components of airway dysfunction to provide greater insight into specific pathophysiologic mechanisms in airway disease.
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Affiliation(s)
- David S Southam
- Firestone Institute for Respiratory Health, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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McVicker CG, Leung SY, Kanabar V, Moir LM, Mahn K, Chung KF, Hirst SJ. Repeated allergen inhalation induces cytoskeletal remodeling in smooth muscle from rat bronchioles. Am J Respir Cell Mol Biol 2007; 36:721-7. [PMID: 17272821 DOI: 10.1165/rcmb.2006-0409oc] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Airway hyperresponsiveness (AHR) is associated with airway wall structural remodeling and alterations in airway smooth muscle (ASM) function. Previously, in bronchioles from Brown Norway rats challenged by repeated ovalbumin (OVA) inhalation, we have reported increased force generation and depletion of smooth muscle contractile proteins. Here, we investigated if cytoskeletal changes in smooth muscle could account for this paradox. Sensitized rats (n = 5/group) were repeatedly challenged with OVA or saline, and the lungs were removed 24 h after the last challenge. Levels of globular (G) and filamentous (F) actin in bronchioles were determined by DNase I inhibition and contraction assessed in intact small bronchioles using a myograph. DNase I inhibition assays showed that G-actin monomers were more abundant ( approximately 1F:2G) in extracts from resting small bronchioles from OVA- or saline-challenged animals. However, while contractile protein levels in bronchioles were reduced by OVA (P < 0.05), the proportion of F:G actin was 1.8-fold greater compared with saline challenge (P < 0.05). Consistent with induction of F-actin after OVA challenge, increases in maximum tension development to carbachol or KCl in small bronchioles from OVA-challenged animals were abrogated (P < 0.01) by actin cytoskeleton disruption with 0.5 microM latrunculin A. Cytoskeletal stabilization of F-actin with 0.1 microM jasplakinolide potentiated maximum contractions to carbachol or KCl (P < 0.05) in bronchioles from OVA- but not saline-treated rats. We conclude that alterations in the composition and/or arrangement of the contractile apparatus after OVA exposure confer enhanced contractile responses, possibly as a result of increased F-actin content. Such a mechanism may have relevance for AHR found in allergic asthma.
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Affiliation(s)
- Clare G McVicker
- King's College London School of Medicine, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, Division of Asthma, Allergy and Lung Biology, London, United kingdom
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Abstract
Allergic asthma is a complex chronic inflammatory disease of the airways and its etiology is multifactorial. It involves the recruitment and activation of many inflammatory and structural cells, all of which release inflammatory mediators that result in typical pathological changes of asthma. The features of asthma addressed in this Brown Norway (BN) rat animal model include an analysis of cellular infiltrations in the lung, inflammatory factors in bronchoalveolar lavage (BAL), total immunoglobulin E (IgE) production in serum, and changes in delayed-onset respiratory reactions upon four inhalation challenges (every 2 wk) with polymeric diphenylmethane diisocyanate (MDI) aerosol in two groups of topically sensitized rats. The dependence on the induction-related variables was analyzed by using almost identical surface area doses but different total doses per animal. This regimen caused acute exacerbations of delayed-onset respiratory reactions, for which intensity increased with each challenge. After the fourth challenge BAL neutrophils, lymphocytes, eosinophils, cell counts, protein, and lactate dehydrogenase (LDH) as well as lung weights were significantly increased in sensitized rats relative to naive but challenged controls. Histopathology revealed activated bronchial lymphatic tissue, increased recruitment of inflammatory cells, the beginning of peribronchial/peribronchiolar fibrosis, thickening of alveolar septae, and vascular hypertrophy. Total IgE in serum was significantly increased in sensitized rats. Thus, high-dose topical induction to, and repeated inhalation challenges with, MDI was associated with a marked neutrophilic and a less consistent eosinophilic inflammatory response. With regard to the relative sensitivity of endpoints, those that integrate independently a series of complex physiological events appeared to be most practical to probe positive responses in this animal model. These include postchallenge changes in Penh to identify respiratory responses delayed in onset as well as inflammatory changes in BAL. In summary, this extension of a previous study that used 16 mg MDI/m(3) instead of 39 mg MDI/m(3) that was used in the current study for challenge exposures demonstrates that protocol variables are most critical for the outcome of test. Moreover, the sensitivity of this bioassay to define the typical asthma phenotype can be markedly improved by measurements of respiratory responses delayed in onset rather than immediate in onset. Accordingly, to increase the efficacy of this asthma model moderately irritant concentrations of the hapten have to be used for challenge and at least three to four adequately spaced challenge exposures are required to elicit a typical asthma phenotype.
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Martin JG, Tamaoka M. Rat models of asthma and chronic obstructive lung disease. Pulm Pharmacol Ther 2005; 19:377-85. [PMID: 16337418 DOI: 10.1016/j.pupt.2005.10.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2005] [Accepted: 10/25/2005] [Indexed: 11/20/2022]
Abstract
The rat has been extensively used to model asthma and somewhat less extensively to model chronic obstructive pulmonary disease (COPD). The features of asthma that have been successfully modeled include allergen-induced airway constriction, eosinophilic inflammation and allergen-induced airway hyperresponsiveness. T-cell involvement has been directly demonstrated using adoptive transfer techniques. Both CD4+ and CD8+ T cells are activated in response to allergen challenge in the sensitized rat and express Thelper2 cytokines (IL-4, IL-5 and IL-13). Repeated allergen exposure causes airway remodeling. Dry gas hyperpnea challenge also evokes increases in lung resistance, allowing exercise-induced asthma to be modeled. COPD is modeled using elastase-induced parenchymal injury to mimic emphysema. Cigarette smoke-induced airspace enlargement occurs but requires months of cigarette exposure. Inflammation and fibrosis of peripheral airways is an important aspect of COPD that is less well modeled. Novel approaches to the treatment of COPD have been reported including treatments aimed at parenchymal regeneration.
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Affiliation(s)
- James G Martin
- Meakins Christie Laboratories, McGill University, Montreal, QUE, Canada.
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Fernandes DJ, McConville JF, Stewart AG, Kalinichenko V, Solway J. Can we differentiate between airway and vascular smooth muscle? Clin Exp Pharmacol Physiol 2005; 31:805-10. [PMID: 15566398 DOI: 10.1111/j.1440-1681.2004.04084.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
1. Airway smooth muscle (ASM) has recently been termed the 'frustrated' cell of the lung given that contraction of ASM has no proven useful physiological function in adults and yet is indelibly associated with pathological conditions by virtue of its unwanted airflow-limiting actions in asthma. In contrast, pulmonary vascular smooth muscle contraction plays an essential role in the control of blood flow through the lung. 2. Little is known of the differences in phenotype between human ASM and pulmonary vascular smooth muscle (VSM) tissues, but differences in contractile protein and transcription factor expression and regulation of contractile protein promoter activity have been documented. Similarly, the embryological signals in mice required for differentiation of ASM versus pulmonary VSM are distinct. 3. Bronchoconstriction in asthma is currently treated with beta2-adrenoceptor agonists, which relax contracted ASM cells. An additional approach may be to use gene therapy to render ASM unable to contract (via disruption of their contractile apparatus organization). 4. Application of ASM-specific gene therapies would rely on minimal actions on other lung smooth muscle tissues, including pulmonary and bronchial vascular smooth muscle. The combination of mRNA analysis of laser-captured microdissected tissue with in situ immunohistochemical staining for protein should be very useful in terms of being able to characterize definitively the differences in mRNA and protein expression between the smooth muscle species of the lung. Any discovery of an ASM-selective target could provide a novel lead for ASM-directed anti-asthma therapy.
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Affiliation(s)
- Darren J Fernandes
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia.
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Ramos-Barbón D, Ludwig MS, Martin JG. Airway remodeling: lessons from animal models. Clin Rev Allergy Immunol 2005; 27:3-21. [PMID: 15347847 DOI: 10.1385/criai:27:1:003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Airway remodeling, an array of persistent tissue structural changes that occurs through a process of injury and dysregulated repair linked to airway chronic inflammation, is presently believed to largely account for the disease mechanisms of asthma. Increases in airway smooth muscle mass are probably the main mechanism causing airway hyperresponsiveness, and changes in the extracellular matrix may stimulate smooth muscle growth and contribute to the mechanics of airway obstruction. The various components of airway remodeling described inhuman asthma have been successfully reproduced in animal models of several species. Most of the data have been contributed by rat models of allergic sensitization and repeated challenge,transgenic mouse models of cytokine overexpression localized to the lung and, more recently, allergen-driven mouse models using wild-type inbred strains. Overall, animal model shave provided significant insights into the mechanisms of airway remodeling and recent technological developments allow us to exploit these models in new directions. However, the challenge of finding new therapeutic strategies that prevent or control airway remodeling,thus providing etiopathogenically oriented treatments for asthma, still stands. Experimental airway remodeling in animals should be an essential tool for treatment discovery in the near future.
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Affiliation(s)
- David Ramos-Barbón
- Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada
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Gosens R, Bos IST, Zaagsma J, Meurs H. Protective effects of tiotropium bromide in the progression of airway smooth muscle remodeling. Am J Respir Crit Care Med 2005; 171:1096-102. [PMID: 15695490 DOI: 10.1164/rccm.200409-1249oc] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Recent findings have demonstrated that muscarinic M(3) receptor stimulation enhances airway smooth muscle proliferation to peptide growth factors in vitro. Because both peptide growth factor expression and acetylcholine release are known to be augmented in allergic airway inflammation, it is possible that anticholinergics protect against allergen-induced airway smooth muscle remodeling in vivo. OBJECTIVE We investigated the effects of treatment with the long-acting muscarinic receptor antagonist tiotropium on airway smooth muscle changes in a guinea pig model of ongoing allergic asthma. RESULTS Twelve weekly repeated allergen challenges induced an increase in airway smooth muscle mass in the noncartilaginous airways. This increase was not accompanied by alterations in cell size, indicating that the allergen-induced changes were entirely from increased airway smooth muscle cell number. Morphometric analysis showed no allergen-induced changes in airway smooth muscle area in the cartilaginous airways. However, repeated ovalbumin challenge enhanced maximal contraction of open tracheal ring preparations ex vivo. This was associated with an increase in smooth muscle-specific myosin expression in the lung. Treatment with inhaled tiotropium considerably inhibited the increase in airway smooth muscle mass, myosin expression, and contractility. CONCLUSIONS These results indicate a prominent role for acetylcholine in allergen-induced airway smooth muscle remodeling in vivo, a process that has been thus far considered to be primarily caused by growth factors and other mediators of inflammation. Therefore, muscarinic receptor antagonists, like the long-acting anticholinergic tiotropium bromide, could be beneficial in preventing chronic airway hyperresponsiveness and decline in lung function in allergic asthma.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University Centre for Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
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Stewart AG, Bonacci JV, Quan L. Factors controlling airway smooth muscle proliferation in asthma. Curr Allergy Asthma Rep 2004; 4:109-15. [PMID: 14769259 DOI: 10.1007/s11882-004-0055-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Airway smooth muscle proliferation has been the focus of considerable attention, as it is a quantitatively important component of the airway wall remodeling response in asthma and has been suggested as a suitable target for the development of novel anti-asthma agents. Such agents are considered likely to reduce airway hyperresponsiveness and, consequently, airway obstruction, resulting in fewer symptoms and exacerbations. Identifying suitable drug targets has proved an elusive goal, as no dominant molecular mechanism for remodeling has emerged. Moreover, recent findings raise some doubt as to whether smooth muscle proliferation per se is the explanation of the increase in smooth muscle cell number in asthma, with alternative explanations including the proposal that cells migrate either from the interstitial compartment or from a circulating precursor stem cell population. Therefore, drug targeting of migration responses should be considered as an alternative approach to regulating the smooth muscle component of airway wall remodeling.
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Affiliation(s)
- Alastair G Stewart
- Department of Pharmacology, University of Melbourne, Grattan Street, Victoria, Australia 3010.
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Abstract
PURPOSE OF REVIEW Asthma is a disease causing significant morbidity and mortality. In the recent past, there has been an explosion of pharmacotherapeutic options attempting to control the disease. Unfortunately, none of the current options offers the promise of prevention or a permanent cure. However, there appear to be exciting, new data emerging to support the hypothesis that the prevention or early treatment of allergic rhinitis, such as with the use of allergen immunotherapy, may help mitigate the severity of bronchial symptoms and even prevent the development of asthma. In this paper, we review recent research published proposing immunotherapy as a means of preventing the development of, or at least ameliorating, allergic asthma. RECENT FINDINGS There is evidence that the upper and lower airways may be considered a single unit, with the nasal and bronchial mucosa having features in common. Epidemiological, pathophysiological and clinical studies have shown that they can be affected by similar inflammatory triggers, with interconnected mechanisms amplifying the inflammatory cascade. Allergic rhinitis is interrelated to, and is a risk factor for, the development of asthma. An evidence-based review validates the successful use of allergen immunotherapy in treating allergic rhinitis and asthma. There is promising evidence advocating its use in the prevention of clinical asthma. SUMMARY This article explores current research pertaining to the use of immunomodulation, such as by using allergen immunotherapy, to ameliorate and prevent the development of allergic asthma.
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Affiliation(s)
- Chitra Dinakar
- Section of Allergy, Asthma and Immunology, The Children's Mercy Hospital, Kansas City, Missouri 64108, USA.
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Törmänen KR, Uller L, Persson CGA, Erjefält JS. Allergen exposure of mouse airways evokes remodeling of both bronchi and large pulmonary vessels. Am J Respir Crit Care Med 2004; 171:19-25. [PMID: 15447945 DOI: 10.1164/rccm.200406-698oc] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Remodeling of airway structures is a well-documented feature of allergic airway inflammation. To investigate whether bronchial remodeling is associated with remodeling of adjacent pulmonary vessels, sensitized mice were subjected to repeated ovalbumin inhalations, and bronchi and pulmonary vessels were subjected to histologic analysis. Allergen challenges induced peribronchial as well as perivascular eosinophilia. Remodeling of systemic airway microcirculation, as studied in tracheal whole-mount preparations, revealed an allergen-induced increase in both the diameter and length of the airway microvessels. Immunostaining for alpha-smooth muscle actin disclosed an increase in smooth muscle mass in both bronchi and large pulmonary vessels. Both bronchi and pulmonary vessels also displayed increased expression of procollagen I and procollagen III. Staining for proliferating cell nuclear antigen revealed increased proliferation of bronchial epithelial and smooth muscle cells as well as pulmonary vascular endothelial and smooth muscle cells. We conclude that central features of remodeling that take place in allergen-exposed airways are present also in the pulmonary vessels. The significance of this finding with respect to occurrence in disease, pathophysiologic importance, and involved mechanisms warrants further investigation.
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Humbles AA, Lloyd CM, McMillan SJ, Friend DS, Xanthou G, McKenna EE, Ghiran S, Gerard NP, Yu C, Orkin SH, Gerard C. A critical role for eosinophils in allergic airways remodeling. Science 2004; 305:1776-9. [PMID: 15375268 DOI: 10.1126/science.1100283] [Citation(s) in RCA: 641] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Features of chronic asthma include airway hyperresponsiveness, inflammatory infiltrates, and structural changes in the airways, termed remodeling. The contribution of eosinophils, cells associated with asthma and allergy, remains to be established. We show that in mice with a total ablation of the eosinophil lineage, increases in airway hyperresponsiveness and mucus secretion were similar to those observed in wild-type mice, but eosinophil-deficient mice were significantly protected from peribronchiolar collagen deposition and increases in airway smooth muscle. These data suggest that eosinophils contribute substantially to airway remodeling but are not obligatory for allergen-induced lung dysfunction, and support an important role for eosinophil-targeted therapies in chronic asthma.
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Affiliation(s)
- Alison A Humbles
- Department of Pediatrics, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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44
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Gosens R, Schaafsma D, Meurs H, Zaagsma J, Nelemans SA. Role of Rho-kinase in maintaining airway smooth muscle contractile phenotype. Eur J Pharmacol 2004; 483:71-8. [PMID: 14709328 DOI: 10.1016/j.ejphar.2003.10.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study aims to investigate the role of Rho-kinase in phenotype switching and proliferation of bovine tracheal smooth muscle. To induce different phenotypic states, bovine tracheal smooth muscle strips were cultured (8 days) in 10% foetal bovine serum (foetal bovine serum, less contractile phenotype) or insulin (1 microM, hypercontractile phenotype) and compared to strips cultured in serum-free medium. In contraction experiments, the Rho-kinase inhibitor (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide (Y-27632, 1 microM) decreased sensitivity to methacholine and KCl and lowered maximal responsiveness to KCl in all strips irrespective of the phenotype present. To investigate the effects of Rho-kinase bovine tracheal smooth muscle phenotypic regulation, strips were pretreated with Y-27632 (1 microM) for 8 days. This resulted in a decreased maximal contractility to both methacholine and KCl, quantitatively comparable to the decrease in contractility induced by platelet-derived growth factor (PDGF, 10 ng/ml). The combination of Y-27632 and PDGF responded additively. Y-27632 did not affect basal or PDGF-induced bovine tracheal smooth muscle cell proliferation, determined both as increases in [3H]thymidine incorporation and cell number. Inhibitors of the p42/p44 mitogen-activated protein kinase (MAPK) pathway, the p38 MAPK pathway and the phosphatidyl inositol (PI) 3-kinase pathway all inhibited PDGF-induced proliferation and phenotype changes. These results show that the functional contribution of Rho-kinase to bovine tracheal smooth muscle contraction is not dependent on phenotypic state. In addition, Rho-kinase is not involved in phenotypic modulation or proliferation induced by PDGF, whereas p42/p44 MAPK, p38 MAPK and PI 3-kinase are. Rho-kinase is, however, a major regulator involved in the basal maintenance of contractility in bovine tracheal smooth muscle.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University Centre for Pharmacy, A. Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
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Gosens R, Nelemans SA, Hiemstra M, Grootte Bromhaar MM, Meurs H, Zaagsma J. Insulin induces a hypercontractile airway smooth muscle phenotype. Eur J Pharmacol 2004; 481:125-31. [PMID: 14637184 DOI: 10.1016/j.ejphar.2003.08.081] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study aims to investigate the effects of insulin on bovine tracheal smooth muscle phenotype in vitro. Contractility of muscle strips and DNA-synthesis ([3H]thymidine incorporation) of isolated cells were used as parameters for smooth muscle phenotyping. Insulin (1 microM) was mitogenic for bovine tracheal smooth muscle and potentiated DNA-synthesis induced by other growth factors. In contrast, after pretreatment of unpassaged bovine tracheal smooth muscle cells in culture, the mitogenic response induced by growth factors was strongly diminished, with no difference in the basal incorporation. Pretreatment of bovine tracheal smooth muscle strips in organ culture with insulin increased maximal contraction to methacholine and KCl. These results show that insulin acutely augments DNA-synthesis in the presence of other growth factors. In contrast, insulin pretreatment induces a hypercontractile phenotype with a decreased mitogenic capacity. This mechanism may be involved in the putative negative association between asthma and type I diabetes. In addition, these findings may have implications for the use of aerosolized insulin in diabetes mellitus.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University Centre for Pharmacy, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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46
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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.
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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.
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47
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McMillan SJ, Lloyd CM. Prolonged allergen challenge in mice leads to persistent airway remodelling. Clin Exp Allergy 2004; 34:497-507. [PMID: 15005746 PMCID: PMC3428844 DOI: 10.1111/j.1365-2222.2004.01895.x] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Inflammatory infiltrates, airway hyper-responsiveness, goblet cell hyperplasia and subepithelial thickening are characteristic of chronic asthma. Current animal models of allergen-induced airway inflammation generally concentrate on the acute inflammation following allergen exposure and fail to mimic all of these features. OBJECTIVE The aim of this study was to use a murine model of prolonged allergen-induced airway inflammation in order to characterize the cells and molecules involved in the ensuing airway remodelling. Moreover, we investigated whether remodelling persists in the absence of continued allergen challenge. METHODS Acute pulmonary eosinophilia and airways hyper-reactivity were induced after six serial allergen challenges in sensitized mice (acute phase). Mice were subsequently challenged three times a week with ovalbumin (OVA) (chronic phase) up to day 55. To investigate the persistence of pathology, one group of mice were left for another 4 weeks without further allergen challenge (day 80). RESULTS The extended OVA challenge protocol caused significant airway remodelling, which was absent in the acute phase. Specifically, remodelling was characterized by deposition of collagen as well as airway smooth muscle and goblet cell hyperplasia. Importantly, these airway changes, together with tissue eosinophilia were sustained in the absence of further allergen challenge. Examination of cytokines revealed a dramatic up-regulation of IL-4 and tumour growth factor-beta1 during the chronic phase. Interestingly, while IL-4 levels were significantly increased during the chronic phase, levels of IL-13 fell. Levels of the Th1-associated cytokine IFN-gamma also increased during the chronic phase. CONCLUSION In conclusion, we have demonstrated that prolonged allergen challenge results in persistent airway wall remodelling.
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Affiliation(s)
- S J McMillan
- Leukocyte Biology Section, Division of Biomedical Sciences, Faculty of Medicine, Imperial College, London, UK
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Woodruff PG, Dolganov GM, Ferrando RE, Donnelly S, Hays SR, Solberg OD, Carter R, Wong HH, Cadbury PS, Fahy JV. Hyperplasia of Smooth Muscle in Mild to Moderate Asthma without Changes in Cell Size or Gene Expression. Am J Respir Crit Care Med 2004; 169:1001-6. [PMID: 14726423 DOI: 10.1164/rccm.200311-1529oc] [Citation(s) in RCA: 300] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bronchial hyperresponsiveness in mild to moderate asthma may result from airway smooth muscle cell proliferation or acquisition of a hypercontractile phenotype. Because these cells have not been well characterized in mild to moderate asthma, we examined the morphometric and gene expression characteristics of smooth muscle cells in this subgroup of patients with asthma. Using bronchial biopsies from 14 subjects with mild to moderate asthma and 15 control subjects, we quantified smooth muscle cell morphology by stereology and the expression of a panel of genes related to a hypercontractile phenotype of airway smooth muscle, using laser microdissection and two-step real-time polymerase chain reaction. We found that airway smooth muscle cell size was similar in both groups, but cell number was nearly twofold higher in subjects with asthma (p = 0.03), and the amount of smooth muscle in the submucosa was increased 50-83% (p < 0.005). Gene expression profiling in smooth muscle cells showed no difference in the expression of genes encoding phenotypic markers in cells from healthy subjects and subjects with asthma (all p > 0.1). We conclude that airway smooth muscle proliferation is a pathologic characteristic of subjects with mild to moderate asthma. However, smooth muscle cells in mild to moderate asthma do not show hypertrophy or gene expression changes of a hypercontractile phenotype observed in vitro.
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Affiliation(s)
- Prescott G Woodruff
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, and Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA.
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49
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Eynott PR, Nath P, Leung SY, Adcock IM, Bennett BL, Chung KF. Allergen-induced inflammation and airway epithelial and smooth muscle cell proliferation: role of Jun N-terminal kinase. Br J Pharmacol 2003; 140:1373-80. [PMID: 14623764 PMCID: PMC1574155 DOI: 10.1038/sj.bjp.0705569] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Revised: 09/05/2003] [Accepted: 10/08/2003] [Indexed: 11/09/2022] Open
Abstract
Chronic cellular inflammation and airway wall remodelling with subepithelial fibrosis and airway smooth muscle (ASM) cell hyperplasia are features of chronic asthma. Jun N-terminal kinase (JNK) may be implicated in these processes by regulating the transcriptional activity of activator protein (AP)-1. We examined the effects of an inhibitor of JNK, SP600125 (anthra [1,9-cd] pyrazole-6 (2 H)-one), in a model of chronic allergic inflammation in the rat. Rats sensitised to ovalbumin (OA) were exposed to OA-aerosol every third day on six occasions and were treated with SP600125 (30 mg kg-1 b.i.d; 360 mg in total) for 12 days, starting after the second through to the sixth OA exposure. We measured eosinophilic and T-cell inflammation in the airways, proliferation of ASM cells and epithelial cells by incorporation of bromodeoxyuridine (BrdU), and bronchial responsiveness to acetylcholine. SP600125 significantly reduced the number of eosinophils (P<0.05) and lymphocytes (P<0.05) in bronchoalveolar lavage fluid, suppressed eosinophilic (P<0.05) and CD2+ T-cell (P<0.05) infiltration within the bronchial submucosa, and the increased DNA incorporation in ASM (P<0.05) and epithelial cell incorporation (P<0.05). SP600125 did not alter bronchial hyper-responsiveness observed after chronic allergen exposure. Pathways regulated by JNK positively regulate ASM cell proliferation and allergic cellular inflammation following chronic allergen exposure.
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Affiliation(s)
- Paul R Eynott
- National Heart & Lung Institute, Imperial College School of Medicine, Dovehouse St, London SW3 6LY
| | - Puneeta Nath
- National Heart & Lung Institute, Imperial College School of Medicine, Dovehouse St, London SW3 6LY
| | - Sum-Yee Leung
- National Heart & Lung Institute, Imperial College School of Medicine, Dovehouse St, London SW3 6LY
| | - Ian M Adcock
- National Heart & Lung Institute, Imperial College School of Medicine, Dovehouse St, London SW3 6LY
| | | | - K Fan Chung
- National Heart & Lung Institute, Imperial College School of Medicine, Dovehouse St, London SW3 6LY
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Martin JG, Ramos-Barbón D. Airway smooth muscle growth from the perspective of animal models. Respir Physiol Neurobiol 2003; 137:251-61. [PMID: 14516730 DOI: 10.1016/s1569-9048(03)00151-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Airway smooth muscle maintains airway tone and may assist in adjusting ventilation distribution within the normal lung. Alterations in the properties or the quantity of ASM are likely responsible for some instances of airways hyperresponsiveness to bronchoconstrictive stimuli that is a characteristic of diseases such as asthma. Morphometric studies have shown an increase in the mass of ASM in human asthmatic airways. Animal models have been developed that confirm that ASM can be induced to grow by allergic sensitization and challenge. Growth is in large part by hyperplasia as measured by incorporation of bromodeoxyuridine as a marker of the S-phase of the cell cycle. T cells, in particular CD4+ cells, may participate in the stimulation of growth of ASM by allergen challenge. The growth factors responsible for the increase in ASM are as yet unidentified but two mediators associated with allergic airway responses, cysteinyl leukotrienes and endothelin, have been implicated using specific receptor antagonists. The links between T cells and the biochemical mediators of growth have not been established.
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Affiliation(s)
- James G Martin
- Department of Medicine, Meakins-Christie Laboratories, McGill University, 3626 Urbain Street, Montreal, QC, Canada H2X 2P2.
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