1
|
The BNT162b2 mRNA COVID-19 Vaccine Increases the Contractile Sensitivity to Histamine and Parasympathetic Activation in a Human Ex Vivo Model of Severe Eosinophilic Asthma. Vaccines (Basel) 2023; 11:vaccines11020282. [PMID: 36851160 PMCID: PMC9965850 DOI: 10.3390/vaccines11020282] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
The BNT162b2 COVID-19 vaccine is composed of lipid-nanoparticles (LNP) containing the mRNA that encodes for SARS-CoV-2 spike glycoprotein. Bronchospasm has been reported as an early reaction after COVID-19 mRNA vaccines in asthmatic patients. The aim of this study was to investigate the acute impact of BNT162b2 in a human ex vivo model of severe eosinophilic asthma. Passively sensitized human isolated bronchi were challenged with the platelet-activating factor to reproduce ex vivo the hyperresponsiveness of airways of patients suffering from severe eosinophilic asthma. BNT162b2 was tested on the contractile sensitivity to histamine and parasympathetic activation via electrical field stimulation (EFS); some experiments were performed after mRNA denaturation. BNT162b2 increased the resting tone (+11.82 ± 2.27%) and response to histamine in partially contracted tissue (+42.97 ± 9.64%) vs. the control (p < 0.001); it also shifted the concentration-response curve to histamine leftward (0.76 ± 0.09 logarithm) and enhanced the response to EFS (+28.46 ± 4.40%) vs. the control. Denaturation did not significantly modify (p > 0.05) the effect of BNT162b2. BNT162b2 increases the contractile sensitivity to histamine and parasympathetic activation in hyperresponsive airways, a detrimental effect not related to the active component but to some excipient. A possible candidate for the bronchospasm elicited by BNT162b2 could be the polyethylene glycol/macrogol used to produce LNP.
Collapse
|
2
|
Xu S, Karmacharya N, Woo J, Cao G, Guo C, Gow A, Panettieri RA, Jude JA. Starving a Cell Promotes Airway Smooth Muscle Relaxation: Inhibition of Glycolysis Attenuates Excitation-Contraction Coupling. Am J Respir Cell Mol Biol 2023; 68:39-48. [PMID: 36227725 PMCID: PMC9817909 DOI: 10.1165/rcmb.2021-0495oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 10/13/2022] [Indexed: 02/05/2023] Open
Abstract
Bronchomotor tone modulated by airway smooth muscle shortening represents a key mechanism that increases airway resistance in asthma. Altered glucose metabolism in inflammatory and airway structural cells is associated with asthma. Although these observations suggest a causal link between glucose metabolism and airway hyperresponsiveness, the mechanisms are unclear. We hypothesized that glycolysis modulates excitation-contraction coupling in human airway smooth muscle (HASM) cells. Cultured HASM cells from human lung donors were subject to metabolic screenings using Seahorse XF cell assay. HASM cell monolayers were treated with vehicle or PFK15 (1-(Pyridin-4-yl)-3-(quinolin-2-yl)prop-2-en-1-one), an inhibitor of PFKFB3 (PFK-1,6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3) that generates an allosteric activator for glycolysis rate-limiting enzyme PFK1 (phosphofructokinase 1), for 5-240 minutes, and baseline and agonist-induced phosphorylation of MLC (myosin light chain), MYPT1 (myosin phosphatase regulatory subunit 1), Akt, RhoA, and cytosolic Ca2+ were determined. PFK15 effects on metabolic activity and contractile agonist-induced bronchoconstriction were determined in human precision-cut lung slices. Inhibition of glycolysis attenuated carbachol-induced excitation-contraction coupling in HASM cells. ATP production and bronchodilator-induced cAMP concentrations were also attenuated by glycolysis inhibition in HASM cells. In human small airways, glycolysis inhibition decreased mitochondrial respiration and ATP production and attenuated carbachol-induced bronchoconstriction. The findings suggest that energy depletion resulting from glycolysis inhibition is a novel strategy for ameliorating HASM cell shortening and bronchoprotection of human small airways.
Collapse
Affiliation(s)
- Shengjie Xu
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
- Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey; and
| | - Nikhil Karmacharya
- Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey; and
| | - Joanna Woo
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
| | - Gaoyuan Cao
- Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey; and
| | - Changjiang Guo
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
| | - Andrew Gow
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
| | - Reynold A. Panettieri
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
- Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey; and
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Joseph A. Jude
- Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Piscataway, New Jersey
- Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey; and
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| |
Collapse
|
3
|
Camoretti-Mercado B, Lockey RF. Airway smooth muscle pathophysiology in asthma. J Allergy Clin Immunol 2021; 147:1983-1995. [PMID: 34092351 DOI: 10.1016/j.jaci.2021.03.035] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/06/2021] [Accepted: 03/16/2021] [Indexed: 02/08/2023]
Abstract
The airway smooth muscle (ASM) cell plays a central role in the pathogenesis of asthma and constitutes an important target for treatment. These cells control muscle tone and thus regulate the opening of the airway lumen and air passage. Evidence indicates that ASM cells participate in the airway hyperresponsiveness as well as the inflammatory and remodeling processes observed in asthmatic subjects. Therapeutic approaches require a comprehensive understanding of the structure and function of the ASM in both the normal and disease states. This review updates current knowledge about ASM and its effects on airway narrowing, remodeling, and inflammation in asthma.
Collapse
Affiliation(s)
- Blanca Camoretti-Mercado
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Fla.
| | - Richard F Lockey
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Fla
| |
Collapse
|
4
|
Kibalina IV, Tsybikov NN. The role of endothelin-1 and its autoantibodies in the pathogenesisof atopic dermatitis: a case-control study. VESTNIK DERMATOLOGII I VENEROLOGII 2021. [DOI: 10.25208/vdv478] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background. Atopic dermatitis is a chronic multifactorial dermatosis with a complex pathophysiological basis. One of the poorly studied links in the pathogenesis of the disease is endothelin-1. Its main biological effects include pronounced vasoconstriction of blood vessels.
Aim. To study the role of endothelin-1 and its autoantibodies in the pathogenesis of atopic dermatitis.
Materials and methods. The study included 40 patients with common and limited forms of atopic dermatitis in the period of exacerbation and remission. The concentration of endothelin-1 and autoantibodies to it in the blood serum was determined by the ELISA method. Statistical processing of the obtained data was performed using Statistica 6.0. Statistical significance was determined at p 0.05.
Results. High concentrations of endothelin-1 and autoantibodies to it were determined during the exacerbation of the disease. When the clinical picture was resolved; the concentration of endothelin-1 and autoantibodies to it significantly decreased; but remained higher than the control group. Based on the data obtained; it can be assumed that an increase in the concentration of endothelin-1 may be a marker of white dermographism and a regulator of the microcirculation process in the skin.
Conclusions. A high level of endothelin-1 contributes to the development of inflammatory reactions in the skin; white dermographism and itching. Endothelin-1 receptors may be potential aim for targeted therapy of atopic dermatitis.
Collapse
|
5
|
Anthracopoulos MB, Everard ML. Asthma: A Loss of Post-natal Homeostatic Control of Airways Smooth Muscle With Regression Toward a Pre-natal State. Front Pediatr 2020; 8:95. [PMID: 32373557 PMCID: PMC7176812 DOI: 10.3389/fped.2020.00095] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/24/2020] [Indexed: 12/20/2022] Open
Abstract
The defining feature of asthma is loss of normal post-natal homeostatic control of airways smooth muscle (ASM). This is the key feature that distinguishes asthma from all other forms of respiratory disease. Failure to focus on impaired ASM homeostasis largely explains our failure to find a cure and contributes to the widespread excessive morbidity associated with the condition despite the presence of effective therapies. The mechanisms responsible for destabilizing the normal tight control of ASM and hence airways caliber in post-natal life are unknown but it is clear that atopic inflammation is neither necessary nor sufficient. Loss of homeostasis results in excessive ASM contraction which, in those with poor control, is manifest by variations in airflow resistance over short periods of time. During viral exacerbations, the ability to respond to bronchodilators is partially or almost completely lost, resulting in ASM being "locked down" in a contracted state. Corticosteroids appear to restore normal or near normal homeostasis in those with poor control and restore bronchodilator responsiveness during exacerbations. The mechanism of action of corticosteroids is unknown and the assumption that their action is solely due to "anti-inflammatory" effects needs to be challenged. ASM, in evolutionary terms, dates to the earliest land dwelling creatures that required muscle to empty primitive lungs. ASM appears very early in embryonic development and active peristalsis is essential for the formation of the lungs. However, in post-natal life its only role appears to be to maintain airways in a configuration that minimizes resistance to airflow and dead space. In health, significant constriction is actively prevented, presumably through classic negative feedback loops. Disruption of this robust homeostatic control can develop at any age and results in asthma. In order to develop a cure, we need to move from our current focus on immunology and inflammatory pathways to work that will lead to an understanding of the mechanisms that contribute to ASM stability in health and how this is disrupted to cause asthma. This requires a radical change in the focus of most of "asthma research."
Collapse
Affiliation(s)
| | - Mark L. Everard
- Division of Paediatrics & Child Health, Perth Children's Hospital, University of Western Australia, Perth, WA, Australia
| |
Collapse
|
6
|
O'Sullivan MJ, Lan B. The Aftermath of Bronchoconstriction. ACTA ACUST UNITED AC 2019; 2:0108031-108036. [PMID: 32328569 DOI: 10.1115/1.4042318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/30/2018] [Indexed: 11/08/2022]
Abstract
Asthma is characterized by chronic airway inflammation, airway remodeling, and excessive constriction of the airway. Detailed investigation exploring inflammation and the role of immune cells has revealed a variety of possible mechanisms by which chronic inflammation drives asthma development. However, the underlying mechanisms of asthma pathogenesis still remain poorly understood. New evidence now suggests that mechanical stimuli that arise during bronchoconstriction may play a critical role in asthma development. In this article, we review the mechanical effect of bronchoconstriction and how these mechanical stresses contribute to airway remodeling independent of inflammation.
Collapse
Affiliation(s)
- Michael J O'Sullivan
- Department of Environmental Health, Harvard T. H. Chan School of Public Health, 665 Huntington Avenue, 1-G07, Boston, MA 02115
| | - Bo Lan
- Department of Environmental Health, Harvard T. H. Chan School of Public Health, 665 Huntington Avenue, 1-G07, Boston, MA 02115 e-mail:
| |
Collapse
|
7
|
Wang Y, Wang A, Zhang M, Zeng H, Lu Y, Liu L, Li J, Deng L. Artesunate attenuates airway resistance in vivo and relaxes airway smooth muscle cells in vitro via bitter taste receptor-dependent calcium signalling. Exp Physiol 2018; 104:231-243. [PMID: 30379382 DOI: 10.1113/ep086824] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 10/18/2018] [Indexed: 01/20/2023]
Abstract
NEW FINDINGS What is the central question of this study? The aim of this study was to evaluate artesunate for its use as a bronchodilator in asthma treatment. What is the main finding and its importance? We found that artesunate reduces airway resistance in both normal and ovalbumin-treated Balb/c mice in vivo. Artesunate reduces traction force while inducing Ca2+ influx into cultured airway smooth muscle cells in vitro, most probably via the bitter taste receptor. These findings provide important evidence at both animal and cellular levels that artesunate might potentially be used as a bronchodilator for treating obstructive airway diseases, such as asthma. ABSTRACT Following the surprising discovery that bitter taste receptors (TAS2Rs) expressed in the lung and can be stimulated to relax airway smooth muscle cells (ASMCs), there is great interest in searching for a bitter taste receptor agonist as a new bronchodilator for asthma therapy. Among the great many other natural bitter substances, artesunate is of special interest to be evaluated for this purpose because of its pharmacological value as a derivative from the well-known anti-malarial, artemisinin. Therefore, in this study we treated either normal or ovalbumin (OVA)-induced asthmatic Balb/c mice in vivo with artesunate (30, 60 or 120 μg) via aerosol inhalation. Subsequently, we measured the airway resistance of the mice in the presence or absence of artesunate. In addition, we treated either mouse or human ASMCs cultured in vitro with artesunate (0.25-2.0 mM) and then measured the traction force and [Ca2+ ]i flux of the cells in the presence or absence of artesunate. The results demonstrate that artesunate attenuated airway resistance in a dose-dependent manner in both the normal and the OVA-treated mice, but more potently in the latter. The in vivo efficacy of artesunate at 120 μg was comparable to that of the conventional bronchodilator, salbutamol, at 3 μg in terms of the reduction in airway resistance. Artesunate also reduced traction force and induced an increase in [Ca2+ ]i in the cultured ASMCs, which was mediated, at least in part, by TAS2R signalling in the human ASMCs. These results together suggest that artesunate might potentially be a cheap and safe bronchodilator to complement the current therapy of asthma.
Collapse
Affiliation(s)
- Yue Wang
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China.,School of Pharmaceutical Engineering and Life Science & School of Nursing, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Aili Wang
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China.,School of Pharmaceutical Engineering and Life Science & School of Nursing, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Ming Zhang
- Department of Thoracic and Cardiovascular Surgery, Changzhou No. 2 People's Hospital, Affiliated to Nanjing Medical University, Changzhou, Jiangsu, 213003, China
| | - Huilong Zeng
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Yun Lu
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Lei Liu
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Jingjing Li
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China
| | - Linhong Deng
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164, China.,School of Pharmaceutical Engineering and Life Science & School of Nursing, Changzhou University, Changzhou, Jiangsu, 213164, China
| |
Collapse
|
8
|
Kazimierová I, Pappová L, Šútovská M, Fraňová S. The effect of short-term and long-term application of fisetin on experimentally induced airway hyperreactivity. EUROPEAN PHARMACEUTICAL JOURNAL 2017. [DOI: 10.1515/afpuc-2017-0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background: Fisetin, a derivate from the flavonol group may possess a variety of pharmacological effects. The aim of the presented study was to evaluate the bronchodilatory effect of fisetin after the acute or the chronic administration to guinea pigs with allergic airway inflammation.
Methods: Experimental animals were sensitized and challenged by ovalbumin. Fisetin was administered in dose 5mg/kg/p.o., either once after the end of 21-days sensitization or daily during the 21-days sensitization. By using the whole-body plethysmograph, we monitored the specific airway resistance, a parameter of airway hyperreactivity in vivo. The changes of the specific airway resistance were evaluated after the short-term inhalation of the bronchoconstriction mediator-histamine (10−6 mol.1−1).
Results: Our results showed that the short-term as well as the long-term administration of fisetin caused decrease of the specific airway resistance values. The bronchodilatory effect of fisetin was comparable to the long-acting beta2 sympathomimetic – salmeterol after the long-term administration. The measurements of the bronchodilatory activity after single administration have revealed more prolonged effect of fisetin comparing to the short-acting beta2 sympathomimetic – salbutamol, as this remained even after the 5 hours, when salbutamol was already ineffective.
Conclusion: In conclusion, flavonol – fisetin has shown bronchodilatory potential. In the light of this fact, fisetin may represent potential substance that can be effective in both prevention as well as control of airway inflammation symptoms.
Collapse
Affiliation(s)
- I. Kazimierová
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Biomedical Center Martin , Martin , Slovak Republic
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Department of Pharmacology , Martin , Slovak Republic
| | - L. Pappová
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Department of Pharmacology , Martin , Slovak Republic
| | - M. Šútovská
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Department of Pharmacology , Martin , Slovak Republic
| | - S. Fraňová
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Biomedical Center Martin , Martin , Slovak Republic
- Comenius University in Bratislava , Jessenius Faculty of Medicine in Martin, Department of Pharmacology , Martin , Slovak Republic
| |
Collapse
|
9
|
Léguillette R, Tohver T, Bond SL, Nicol JA, McDonald KJ. Effect of Dexamethasone and Fluticasone on Airway Hyperresponsiveness in Horses With Inflammatory Airway Disease. J Vet Intern Med 2017; 31:1193-1201. [PMID: 28568169 PMCID: PMC5508307 DOI: 10.1111/jvim.14740] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/15/2017] [Accepted: 04/19/2017] [Indexed: 11/30/2022] Open
Abstract
Background Airway hyperresponsiveness (AWHR), expressed as hypersensitivity (PC75RL) or hyperreactivity (slope of the histamine dose‐response curve), is a feature of inflammatory airway disease (IAD) or mild equine asthma in horses. Glucocorticoids are used empirically to treat IAD. Objectives To determine whether dexamethasone (DEX) (0.05 mg/kg IM q24h) and inhaled fluticasone (FLUT) (3,000 μg q12h) administered by inhalation are effective in decreasing AWHR, lung inflammation, and clinical signs in horses with IAD. Methods A randomized crossover study design was used. Eight horses with IAD were assigned to a treatment group with either DEX or FLUT. Measured outcomes included lung mechanics during bronchoprovocative challenges, bronchoalveolar lavage fluid (BALF) cytology, and scoring of clinical signs during exercise. Results Dexamethasone and FLUT abolished the increase in RL by 75% at any histamine bronchoprovocative dose in all horses after the first week of treatment. However, after 2 weeks of FLUT treatment, 1 horse redeveloped hypersensitivity. There was a significant decrease in the number of lymphocytes after treatment with both DEX and FLUT (P = .039 for both) but no significant differences in other BALF cell types or total cell counts (P > .05). There was no difference in the scoring of the clinical signs during each treatment and washout period (P > .05). Conclusions and Clinical Importance Both DEX and FLUT treatments significantly inhibit airway hypersensitivity and hyperreactivity in horses with IAD. There are no significant effects on the clinical signs or the number of inflammatory cells (except lymphocytes) in BALF. The treatments have no residual effect 3 weeks after discontinuation.
Collapse
Affiliation(s)
- R Léguillette
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - T Tohver
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - S L Bond
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - J A Nicol
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - K J McDonald
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
10
|
Valon L, Marín-Llauradó A, Wyatt T, Charras G, Trepat X. Optogenetic control of cellular forces and mechanotransduction. Nat Commun 2017; 8:14396. [PMID: 28186127 PMCID: PMC5309899 DOI: 10.1038/ncomms14396] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 12/19/2016] [Indexed: 02/07/2023] Open
Abstract
Contractile forces are the end effectors of cell migration, division, morphogenesis, wound healing and cancer invasion. Here we report optogenetic tools to upregulate and downregulate such forces with high spatiotemporal accuracy. The technology relies on controlling the subcellular activation of RhoA using the CRY2/CIBN light-gated dimerizer system. We fused the catalytic domain (DHPH domain) of the RhoA activator ARHGEF11 to CRY2-mCherry (optoGEF-RhoA) and engineered its binding partner CIBN to bind either to the plasma membrane or to the mitochondrial membrane. Translocation of optoGEF-RhoA to the plasma membrane causes a rapid and local increase in cellular traction, intercellular tension and tissue compaction. By contrast, translocation of optoGEF-RhoA to mitochondria results in opposite changes in these physical properties. Cellular changes in contractility are paralleled by modifications in the nuclear localization of the transcriptional regulator YAP, thus showing the ability of our approach to control mechanotransductory signalling pathways in time and space.
Collapse
Affiliation(s)
- Léo Valon
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain
| | | | - Thomas Wyatt
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
- London Centre for Nanotechnology, London WC1H 0AH, UK
| | - Guillaume Charras
- London Centre for Nanotechnology, London WC1H 0AH, UK
- Department of Cell and Developmental Biology and Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain
- Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Barcelona 08028, Spain
| |
Collapse
|
11
|
Wang Y, Lu Y, Luo M, Shi X, Pan Y, Zeng H, Deng L. Evaluation of pharmacological relaxation effect of the natural product naringin on in vitro cultured airway smooth muscle cells and in vivo ovalbumin-induced asthma Balb/c mice. Biomed Rep 2016; 5:715-722. [PMID: 28101344 DOI: 10.3892/br.2016.797] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/29/2016] [Indexed: 12/23/2022] Open
Abstract
Asthma has become a common chronic respiratory disease worldwide and its prevalence is predicted to continue increasing in the next decade, particularly in developing countries. A key component in asthma therapy is to alleviate the excessive bronchial airway narrowing ultimately due to airway smooth muscle contraction, which is often facilitated by a smooth muscle relaxant, such as the β2-adrenergic agonists. Recently, bitter taste receptor (TAS2R) agonists, including saccharin and chloroquine, have been found to potently relax the airway smooth muscle cells (ASMCs) via intracellular Ca2+ signaling. This inspires a great interest in screening the vast resource of natural bitter substances for potential bronchodilatory drugs. In the present study, the relaxation effect of naringin, a compound extracted from common grapefruit, on ASMCs cultured in vitro or bronchial airways of Balb/c mice in vivo was evaluated. The results demonstrated that, when exposed to increasing doses of naringin (0.125, 0.25, 0.5 and 1.0 mM), the traction force generated by the cultured ASMCs decreased progressively, while the intracellular calcium flux signaling in the ASMCs increased. When inhaled at increasing doses (15, 30 and 60 µg), naringin also dose-dependently reduced the bronchial airway resistance of the normal and ovalbumin-induced asthma Balb/c mice in response to challenge with methacholine. In conclusion, these findings indicate that naringin was able to effectively relax murine ASMCs in vitro and in vivo, thus suggesting that it is a promising drug agent to be further investigated in the development of novel bronchodilators for the treatment of asthma.
Collapse
Affiliation(s)
- Yue Wang
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Nursing, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Yun Lu
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Mingzhi Luo
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Xiaohao Shi
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Yan Pan
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Huilong Zeng
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| | - Linhong Deng
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Nursing, Changzhou University, Changzhou, Jiangsu 213164, P.R. China; School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu 213164, P.R. China
| |
Collapse
|
12
|
Brown RH, Togias A. Measurement of intraindividual airway tone heterogeneity and its importance in asthma. J Appl Physiol (1985) 2016; 121:223-32. [PMID: 27103654 PMCID: PMC4967252 DOI: 10.1152/japplphysiol.00545.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 04/20/2016] [Indexed: 11/22/2022] Open
Abstract
While airways have some degree of baseline tone, the level and variability of this tone is not known. It is also unclear whether there is a difference in airway tone or in the variability of airway tone between asthmatic and healthy individuals. This study examined airway tone and intraindividual airway tone heterogeneity (variance of airway tone) in vivo in 19 individuals with asthma compared with 9 healthy adults. All participants underwent spirometry, body plethysmography, and high-resolution computed tomography at baseline and after maximum bronchodilation with albuterol. Airway tone was defined as the percent difference in airway diameter after albuterol at total lung capacity compared with baseline. The amount of airway tone in each airway varied both within and between subjects. The average airway tone did not differ significantly between the two groups (P = 0.09), but the intraindividual airway tone heterogeneity did (P = 0.016). Intraindividual airway tone heterogeneity was strongly correlated with airway tone (r = 0.78, P < 0.0001). Also, it was negatively correlated with the magnitude of the distension of the airways from functional residual capacity to total lung capacity at both baseline (r = −0.49, P = 0.03) and after maximum bronchodilation (r = −0.51, P = 0.02) in the asthma, but not the healthy group. However, we did not find any relationship between intraindividual airway tone heterogeneity and conventional lung function outcomes. Intraindividual airway tone heterogeneity appears to be an important characteristic of airway pathophysiology in asthma.
Collapse
Affiliation(s)
- Robert H Brown
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland; Department of Environmental Health Sciences, Division of Physiology, Johns Hopkins University, Baltimore, Maryland; Department of Radiology, Johns Hopkins University, Baltimore, Maryland; and
| | - Alkis Togias
- Department of Medicine, Divisions of Allergy and Clinical Immunology and Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| |
Collapse
|
13
|
Guedes AGP, Deshpande DA, Dileepan M, Walseth TF, Panettieri RA, Subramanian S, Kannan MS. CD38 and airway hyper-responsiveness: studies on human airway smooth muscle cells and mouse models. Can J Physiol Pharmacol 2014; 93:145-53. [PMID: 25594684 DOI: 10.1139/cjpp-2014-0410] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Asthma is an inflammatory disease in which altered calcium regulation, contractility, and airway smooth muscle (ASM) proliferation contribute to airway hyper-responsiveness and airway wall remodeling. The enzymatic activity of CD38, a cell-surface protein expressed in human ASM cells, generates calcium mobilizing second messenger molecules such as cyclic ADP-ribose. CD38 expression in human ASM cells is augmented by cytokines (e.g., TNF-α) that requires the activation of MAP kinases and the transcription factors, NF-κB and AP-1, and is post-transcriptionally regulated by miR-140-3p and miR-708 by binding to 3' Untranslated Region of CD38 as well as by modulating the activation of signaling mechanisms involved in its regulation. Mice deficient in Cd38 exhibit reduced airway responsiveness to inhaled methacholine relative to the response in wild-type mice. Intranasal challenge of Cd38-deficient mice with TNF-α or IL-13, or the environmental fungus Alternaria alternata, causes significantly attenuated methacholine responsiveness compared with wild-type mice, with comparable airway inflammation. Reciprocal bone marrow transfer studies revealed partial restoration of airway hyper-responsiveness to inhaled methacholine in the Cd38-deficient mice. These studies provide evidence for CD38 involvement in the development of airway hyper-responsiveness; a hallmark feature of asthma. Future studies aimed at drug discovery and delivery targeting CD38 expression and (or) activity are warranted.
Collapse
Affiliation(s)
- Alonso G P Guedes
- a Department of Surgical & Radiological Sciences, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
A systematic review of validated methods to capture acute bronchospasm using administrative or claims data. Vaccine 2014; 31 Suppl 10:K12-20. [PMID: 24331069 DOI: 10.1016/j.vaccine.2013.06.091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 06/08/2013] [Accepted: 06/21/2013] [Indexed: 11/23/2022]
Abstract
PURPOSE To identify and assess billing, procedural, or diagnosis code, or pharmacy claim-based algorithms used to identify acute bronchospasm in administrative and claims databases. METHODS We searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to bronchospasm, wheeze and acute asthma. We also searched the reference lists of included studies. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria. Two reviewers independently extracted data regarding participant and algorithm characteristics. RESULTS Our searches identified 677 citations of which 38 met our inclusion criteria. In these 38 studies, the most commonly used ICD-9 code was 493.x. Only 3 studies reported any validation methods for the identification of bronchospasm, wheeze or acute asthma in administrative and claims databases; all were among pediatric populations and only 2 offered any validation statistics. Some of the outcome definitions utilized were heterogeneous and included other disease based diagnoses, such as bronchiolitis and pneumonia, which are typically of an infectious etiology. One study offered the validation of algorithms utilizing Emergency Department triage chief complaint codes to diagnose acute asthma exacerbations with ICD-9 786.07 (wheezing) revealing the highest sensitivity (56%), specificity (97%), PPV (93.5%) and NPV (76%). CONCLUSIONS There is a paucity of studies reporting rigorous methods to validate algorithms for the identification of bronchospasm in administrative data. The scant validated data available are limited in their generalizability to broad-based populations.
Collapse
|
15
|
Noble PB, Pascoe CD, Lan B, Ito S, Kistemaker LEM, Tatler AL, Pera T, Brook BS, Gosens R, West AR. Airway smooth muscle in asthma: linking contraction and mechanotransduction to disease pathogenesis and remodelling. Pulm Pharmacol Ther 2014; 29:96-107. [PMID: 25062835 DOI: 10.1016/j.pupt.2014.07.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 07/12/2014] [Accepted: 07/15/2014] [Indexed: 02/07/2023]
Abstract
Asthma is an obstructive airway disease, with a heterogeneous and multifactorial pathogenesis. Although generally considered to be a disease principally driven by chronic inflammation, it is becoming increasingly recognised that the immune component of the pathology poorly correlates with the clinical symptoms of asthma, thus highlighting a potentially central role for non-immune cells. In this context airway smooth muscle (ASM) may be a key player, as it comprises a significant proportion of the airway wall and is the ultimate effector of acute airway narrowing. Historically, the contribution of ASM to asthma pathogenesis has been contentious, yet emerging evidence suggests that ASM contractile activation imparts chronic effects that extend well beyond the temporary effects of bronchoconstriction. In this review article we describe the effects that ASM contraction, in combination with cellular mechanotransduction and novel contraction-inflammation synergies, contribute to asthma pathogenesis. Specific emphasis will be placed on the effects that ASM contraction exerts on the mechanical properties of the airway wall, as well as novel mechanisms by which ASM contraction may contribute to more established features of asthma such as airway wall remodelling.
Collapse
Affiliation(s)
- Peter B Noble
- School of Anatomy, Physiology and Human Biology, University of Western Australia, WA, Australia
| | - Chris D Pascoe
- Center for Heart Lung Innovation, University of British Columbia, BC, Canada
| | - Bo Lan
- Center for Heart Lung Innovation, University of British Columbia, BC, Canada; Bioengineering College, Chongqing University, Chongqing, China
| | - Satoru Ito
- Department of Respiratory Medicine, Nagoya University, Aichi, Japan
| | - Loes E M Kistemaker
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Amanda L Tatler
- Division of Respiratory Medicine, University of Nottingham, United Kingdom
| | - Tonio Pera
- Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Bindi S Brook
- School of Mathematical Sciences, University of Nottingham, United Kingdom
| | - Reinoud Gosens
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Adrian R West
- Department of Physiology, University of Manitoba, MB, Canada; Biology of Breathing, Manitoba Institute of Child Health, MB, Canada.
| |
Collapse
|
16
|
Abstract
Isolated tracheal rings have often been used to directly measure the contractile output of airway smooth muscle (ASM). Here, we describe the method for excising murine tracheas, mounting tracheal rings in organ baths, and measuring the isometric forces generated by the ASM when stimulated by drug additions or electric field stimulation. The apparatus for the setup and the pathways responsible for stimulation are detailed. Examples of the responses and analyses of two types of ASM stimulation are illustrated: (1) the carbachol concentration-response curve and (2) the frequency-response curve elicited by electric field stimulation.
Collapse
|
17
|
Lee SL, Nekouzadeh A, Butler B, Pryse KM, McConnaughey WB, Nathan AC, Legant WR, Schaefer PM, Pless RB, Elson EL, Genin GM. Physically-induced cytoskeleton remodeling of cells in three-dimensional culture. PLoS One 2012; 7:e45512. [PMID: 23300512 PMCID: PMC3531413 DOI: 10.1371/journal.pone.0045512] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 08/20/2012] [Indexed: 01/15/2023] Open
Abstract
Characterizing how cells in three-dimensional (3D) environments or natural tissues respond to biophysical stimuli is a longstanding challenge in biology and tissue engineering. We demonstrate a strategy to monitor morphological and mechanical responses of contractile fibroblasts in a 3D environment. Cells responded to stretch through specific, cell-wide mechanisms involving staged retraction and reinforcement. Retraction responses occurred for all orientations of stress fibers and cellular protrusions relative to the stretch direction, while reinforcement responses, including extension of cellular processes and stress fiber formation, occurred predominantly in the stretch direction. A previously unreported role of F-actin clumps was observed, with clumps possibly acting as F-actin reservoirs for retraction and reinforcement responses during stretch. Responses were consistent with a model of cellular sensitivity to local physical cues. These findings suggest mechanisms for global actin cytoskeleton remodeling in non-muscle cells and provide insight into cellular responses important in pathologies such as fibrosis and hypertension.
Collapse
Affiliation(s)
- Sheng-Lin Lee
- Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri, United States of America
| | - Ali Nekouzadeh
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, United States of America
| | - Boyd Butler
- Department of Biological Sciences Texas Tech University, Lubbock, Texas, United States of America
| | - Kenneth M. Pryse
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - William B. McConnaughey
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Adam C. Nathan
- Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri, United States of America
| | - Wesley R. Legant
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, United States of America
| | - Pascal M. Schaefer
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Robert B. Pless
- Department of Computer Science and Engineering, Washington University, St. Louis, Missouri, United States of America
| | - Elliot L. Elson
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Guy M. Genin
- Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri, United States of America
| |
Collapse
|
18
|
Tuna BG, Bakker ENTP, VanBavel E. Smooth muscle biomechanics and plasticity: relevance for vascular calibre and remodelling. Basic Clin Pharmacol Toxicol 2011; 110:35-41. [PMID: 21902815 DOI: 10.1111/j.1742-7843.2011.00794.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Blood vessel structure and calibre are not static. Rather, vessels remodel continuously in response to their biomechanical environment. Vascular calibre is dictated by the amount, composition and organization of the elastic extracellular matrix. In addition, the amount and organization of contractile smooth muscle cell (SMC) also need to be regulated. The SMCs are organized such that maximum contractile force generally occurs at diameters slightly below the diameter at full dilation and physiological pressure. Thus, in a remodelling vessel, not only the matrix but also the SMCs need to undergo structural adaptation. Surprisingly little is known on the adaptation of SMC contractile properties in the vasculature. The purpose of this review is to explore this SMC plasticity in the context of vascular remodelling. While not much work on this has been carried out on blood vessels, SMC plasticity is more extensively studied on other hollow structures such as airway and bladder. We therefore include studies on bladder and airway SMCs because of their possible relevance for vascular SMC behaviour. Here, plasticity is thought to form an adaptation allowing maintained function despite large volume changes. In blood vessels, the general match of active and passive diameter-tension relations suggests that SMC plasticity is part of normal vascular physiological adaptation. Vascular SMCs display similar processes and forms of adaptation as seen in nonvascular SMCs. This may become particularly relevant under strong vasoconstriction, when inward cytoskeletal adaptation possibly prevents immediate full dilation. This may contribute to structural inward remodelling as seen in hypertension and flow reduction.
Collapse
Affiliation(s)
- Bilge Guvenc Tuna
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | | |
Collapse
|
19
|
Connolly SC, Smith PG, Fairbank NJ, Lall CA, Cole DJ, Mackinnon JD, Maksym GN. Chronic oscillatory strain induces MLCK associated rapid recovery from acute stretch in airway smooth muscle cells. J Appl Physiol (1985) 2011; 111:955-63. [PMID: 21737821 DOI: 10.1152/japplphysiol.00812.2009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A deep inspiration (DI) temporarily relaxes agonist-constricted airways in normal subjects, but in asthma airways are refractory and may rapidly renarrow, possibly due to changes in the structure and function of airway smooth muscle (ASM). Chronic largely uniaxial cyclic strain of ASM cells in culture causes several structural and functional changes in ASM similar to that in asthma, including increases in contractility, MLCK content, shortening velocity, and shortening capacity. However, changes in recovery from acute stretch similar to a DI have not been measured. We have therefore measured the response and recovery to large stretches of cells modified by chronic stretching and investigated the role of MLCK. Chronic, 10% uniaxial cyclic stretch, with or without a strain gradient, was administered for up to 11 days to cultured cells grown on Silastic membranes. Single cells were then removed from the membrane and subjected to 1 Hz oscillatory stretches up to 10% of the in situ cell length. These oscillations reduced stiffness by 66% in all groups (P < 0.05). Chronically strained cells recovered stiffness three times more rapidly than unstrained cells, while the strain gradient had no effect. The stiffness recovery in unstrained cells was completely inhibited by the MLCK inhibitor ML-7, but recovery in strained cells exhibiting increased MLCK was slightly inhibited. These data suggest that chronic strain leads to enhanced recovery from acute stretch, which may be attributable to the strain-induced increases in MLCK. This may also explain in part the more rapid renarrowing of activated airways following DI in asthma.
Collapse
Affiliation(s)
- Sarah C Connolly
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | | | | | | | | |
Collapse
|
20
|
Sandberg KL, Pinkerton KE, Poole SD, Minton PA, Sundell HW. Fetal nicotine exposure increases airway responsiveness and alters airway wall composition in young lambs. Respir Physiol Neurobiol 2011; 176:57-67. [DOI: 10.1016/j.resp.2010.12.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/21/2010] [Accepted: 12/22/2010] [Indexed: 11/30/2022]
|
21
|
Zhao LM, Ma LJ, Zhang LX, Wu JZ. Shenmai injection inhibiting the extracellular signal regulated kinase-induced human airway smooth muscle proliferation in asthma. Chin J Integr Med 2010; 16:331-6. [PMID: 20697944 DOI: 10.1007/s11655-010-0505-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To investigate the relationship between the proliferation of sensitized human airway smooth muscle cells (HASMCs) and the expression of extracellular signal regulated kinase (ERK) and the effect of Shenmai Injection (SMI) on HASMCs. METHODS The HASMCs cultured in vitro were divided into three groups: (1) control group; (2) sensitized group: containing 10% asthmatic serum; (3) SMI group: further divided into three different concentration subgroups interferred with 10 microL/mL, 50 microL/mL, and 100 microL/mL SMI, respectively. The proliferation of HASMCs was detected using MTT method, the expression of proliferating cell nucleus antigen (PCNA) in HASMCs was detected using immunocytochemical staining, and the expression of phosphoration-ERK1/2 (p-ERK1/2) protein was detected using Western-blot. RESULTS After passive sensitization,: the optical density value (A A(490) value) of HASMCs was significantly increased from 0.366+/-0.086 to 0.839+/- 0.168 (P<0.05). In addition, the expression of PCNA was significantly increased from 28.7%+/-5.9% in the control group to 69.8%+/-7.5% in the sensitized group (P<0.05). At the same time, the expression of p-ERK1/2 in passively sensitized HASMCs was significantly increased compared with the control group (all P<0.05). After application of 10 microL/mL, 50 microL/mL, and 100 microL/mL SMI to the cultured media of passively sensitized group, the A(570) value was significantly decreased from 0.839+/-0.168 to 0.612+/-0.100, 0.412+/-0.092, and 0.339+/-0.077, respectively (P<0.05). Moreover, the expression of PCNA was significantly decreased from 69.8%+/-7.5% to 57.8%+/-6.2%, 40.7%+/-5.4%, and 26.1%+/-5.2%, respectively. At the same time, the expression of p-ERK1/2 in each SMI group was significantly decreased compared with the sensitized group (all P<0.05). CONCLUSION ERK signal transduction pathway may be involved in the airway remodeling in asthma. The expression of ERK can be inhibited by SMI in a dose-dependent manner, thus preventing the proliferation of HASMCs.
Collapse
Affiliation(s)
- Li-min Zhao
- Department of Respiratory Diseases, Henan Province People's Hospital, Zhengzhou 450003, China
| | | | | | | |
Collapse
|
22
|
Dowell ML, Lavoie TL, Lakser OJ, Dulin NO, Fredberg JJ, Gerthoffer WT, Seow CY, Mitchell RW, Solway J. MEK modulates force-fluctuation-induced relengthening of canine tracheal smooth muscle. Eur Respir J 2010; 36:630-7. [PMID: 20110395 DOI: 10.1183/09031936.00160209] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Tidal breathing, and especially deep breathing, is known to antagonise bronchoconstriction caused by airway smooth muscle (ASM) contraction; however, this bronchoprotective effect of breathing is impaired in asthma. Force fluctuations applied to contracted ASM in vitro cause it to relengthen, force-fluctuation-induced relengthening (FFIR). Given that breathing generates similar force fluctuations in ASM, FFIR represents a likely mechanism by which breathing antagonises bronchoconstriction. Thus it is of considerable interest to understand what modulates FFIR, and how ASM might be manipulated to exploit this phenomenon. It was demonstrated previously that p38 mitogen-activated protein kinase (MAPK) signalling regulates FFIR in ASM strips. Here, it was hypothesised that the MAPK kinase (MEK) signalling pathway also modulates FFIR. In order to test this hypothesis, changes in FFIR were measured in ASM treated with the MEK inhibitor, U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene). Increasing concentrations of U0126 caused greater FFIR. U0126 reduced extracellular signal-regulated kinase 1/2 phosphorylation without affecting isotonic shortening or 20-kDa myosin light chain and p38 MAPK phosphorylation. However, increasing concentrations of U0126 progressively blunted phosphorylation of high-molecular-weight caldesmon (h-caldesmon), a downstream target of MEK. Thus changes in FFIR exhibited significant negative correlation with h-caldesmon phosphorylation. The present data demonstrate that FFIR is regulated through MEK signalling, and suggest that the role of MEK is mediated, in part, through caldesmon.
Collapse
Affiliation(s)
- M L Dowell
- Section of Pulmonary Medicine, Dept of Pediatrics, The University of Chicago, 5841 S. Maryland Avenue, MC4064, Chicago, IL 60637, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
The prevalence of childhood obesity has more than tripled over the past five decades. Obesity results in low lung volumes, likely through increased loading of the chest wall and abdomen. The prevalence of asthma in children has paralleled the rise in obesity; obesity may increase the severity of asthma, but a direct link has been difficult to establish. Obesity is a risk factor for obstructive sleep apnea (OSA) in children as well as adults. Obese children may be at increased risk for persistent OSA following adenotonsillectomy treatment for OSA. Severe obesity and OSA may lead to the obesity-hypoventilation syndrome, with hypoxia, hypercapnia, and reduced ventilatory drive. Obesity can increase a child's risk for complications of anesthesia and recovery from surgery.
Collapse
Affiliation(s)
- Elizabeth K Fiorino
- Division of Pulmonary Medicine and Sleep Center, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | |
Collapse
|
24
|
Kim HR, Graceffa P, Ferron F, Gallant C, Boczkowska M, Dominguez R, Morgan KG. Actin polymerization in differentiated vascular smooth muscle cells requires vasodilator-stimulated phosphoprotein. Am J Physiol Cell Physiol 2009; 298:C559-71. [PMID: 20018948 DOI: 10.1152/ajpcell.00431.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Our group has previously shown that vasoconstrictors increase net actin polymerization in differentiated vascular smooth muscle cells (dVSMC) and that increased actin polymerization is linked to contractility of vascular tissue (Kim et al., Am J Physiol Cell Physiol 295: C768-778, 2008). However, the underlying mechanisms are largely unknown. Here, we evaluated the possible functions of the Ena/vasodilator-stimulated phosphoprotein (VASP) family of actin filament elongation factors in dVSMC. Inhibition of actin filament elongation by cytochalasin D decreases contractility without changing myosin light-chain phosphorylation levels, suggesting that actin filament elongation is necessary for dVSM contraction. VASP is the only Ena/VASP protein highly expressed in aorta tissues, and VASP knockdown decreased smooth muscle contractility. VASP partially colocalizes with alpha-actinin and vinculin in dVSMC. Profilin, known to associate with G actin and VASP, also colocalizes with alpha-actinin and vinculin, potentially identifying the dense bodies and the adhesion plaques as hot spots of actin polymerization. The EVH1 domain of Ena/VASP is known to target these proteins to their sites of action. Introduction of an expressed EVH1 domain as a dominant negative inhibits stimulus-induced increases in actin polymerization. VASP phosphorylation, known to inhibit actin polymerization, is decreased during phenylephrine stimulation in dVSMC. We also directly visualized, for the first time, rhodamine-labeled actin incorporation in dVSMC and identified hot spots of actin polymerization in the cell cortex that colocalize with VASP. These results indicate a role for VASP in actin filament assembly, specifically at the cell cortex, that modulates contractility in dVSMC.
Collapse
Affiliation(s)
- Hak Rim Kim
- Dept. of Health Sciences, Boston Univ., 635 Commonwealth Ave, Boston MA 02215, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Oldenburg PJ, Wyatt TA, Sisson JH. Ethanol attenuates contraction of primary cultured rat airway smooth muscle cells. Am J Respir Cell Mol Biol 2009; 43:539-45. [PMID: 19933378 DOI: 10.1165/rcmb.2009-0252oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Airway smooth muscle cells are the main effector cells involved in airway narrowing and have been used to study the signaling pathways involved in asthma-induced airway constriction. Our previous studies demonstrated that ethanol administration to mice attenuated methacholine-stimulated increases in airway responsiveness. Because ethanol administration attenuates airway responsiveness in mice, we hypothesized that ethanol directly blunts the ability of cultured airway smooth muscle cells to shorten. To test this hypothesis, we measured changes in the size of cultured rat airway smooth muscle (RASM) cells exposed to ethanol (100 mM) after treatment with methacholine. Ethanol markedly attenuated methacholine-stimulated cell shortening (methacholine-stimulated length change = 8.3 ± 1.2% for ethanol versus 43.9 ± 1.5% for control; P < 0.001). Ethanol-induced inhibition of methacholine-stimulated cell shortening was reversible 24 hours after removal of alcohol. To determine if ethanol acts through a cGMP-dependent pathway, incubation with ethanol for as little as 15 minutes produced a doubling of cGMP-dependent protein kinase (PKG) activity. Furthermore, treatment with the PKG antagonist analog Rp-8Br-cGMPS (10 μM) inhibited ethanol-induced kinase activation when compared with control-treated cells. In contrast to the effect of ethanol on PKG, ethanol pretreatment did not activate a cAMP-dependent protein kinase. These data demonstrate that brief ethanol exposure reversibly prevents methacholine-stimulated RASM cell contraction. In addition, it appears that this effect is the result of activation of the cGMP/PKG kinase pathway. These findings implicate a direct effect of ethanol on airway smooth muscle cells as the basis for in vivo ethanol effects.
Collapse
Affiliation(s)
- Peter J Oldenburg
- Department of Internal Medicine, Pulmonary, Critical Care, Sleep, & Allergy Division, University of Nebraska Medical Center, Omaha, Nebraska 68198-5910, USA
| | | | | |
Collapse
|
26
|
Allen GB, Leclair TR, von Reyn J, Larrabee YC, Cloutier ME, Irvin CG, Bates JHT. Acid aspiration-induced airways hyperresponsiveness in mice. J Appl Physiol (1985) 2009; 107:1763-70. [PMID: 19797689 DOI: 10.1152/japplphysiol.00572.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The role of gastroesophageal reflux and micro-aspiration as a trigger of airways hyperresponsiveness (AHR) in patients with asthma is controversial. The role of acid reflux and aspiration as a direct cause of AHR in normal subjects is also unclear. We speculated that aspiration of a weak acid with a pH (1.8) equivalent to the upper range of typical gastric contents would lead to AHR in naive mice. We further speculated that modest reductions in aspirate acidity to a level expected during gastric acid suppression therapy (pH 4.0) would impede aspiration-induced AHR. BALB/c female mice were briefly anesthetized with isoflurane and allowed to aspirate 75 microl of saline with HCl (pH 1.8, 4.0, or 7.4) or underwent sham aspiration. Mice were re-anesthetized 2 or 24 h later, underwent tracheostomy, and were coupled to a mechanical ventilator. Forced oscillations were used to periodically measure respiratory impedance (Zrs) following aerosol delivery of saline and increasing doses of methacholine to measure for AHR. Values for elastance (H), airways resistance (R(N)), and tissue damping (G) were derived from Zrs. Aspirate pH of 1.8 led to a significant overall increase in peak R(N), G, and H compared with pH 4.0 and 7.4 at 2 and 24 h. Differences between pH 7.4 and 4.0 were not significant. In mice aspirating pH 1.8 compared with controls, airway lavage fluid contained more neutrophils, higher protein, and demonstrated higher permeability. We conclude that acid aspiration triggers an acute AHR, driven principally by breakdown of epithelial barrier integrity within the airways.
Collapse
Affiliation(s)
- Gilman B Allen
- Department of Medicine, Vermont Lung Center, University of Vermont, Burlington, Vermont, USA.
| | | | | | | | | | | | | |
Collapse
|
27
|
Alteration of airway responsiveness mediated by receptors in ovalbumin-induced asthmatic E3 rats. Acta Pharmacol Sin 2009; 30:965-72. [PMID: 19575000 DOI: 10.1038/aps.2009.61] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AIM Airway hyperresponsiveness is a constant feature of asthma. The aim of the present study was to investigate airway hyperreactivity mediated by contractile and dilative receptors in an ovalbumin (OVA)-induced model of rat asthma. METHODS Asthmatic E3 rats were prepared by intraperitoneal injection with OVA/aluminum hydroxide and then challenged with intranasal instillation of OVA-PBS two weeks later. The myograph method was used to measure the responses of constriction and dilatation in the trachea, main bronchi and lobar bronchi. RESULTS In asthmatic E3 rats, beta(2) adrenoceptor-mediated relaxation of airway smooth muscle pre-contracted with 5-HT was inhibited, and there were no obvious difference in relaxation compared with normal E3 rats. Contraction of lobar bronchi mediated by 5-HT and sarafotoxin 6c was more potent than in the trachea or main bronchi. Airway contractions mediated by the endothelin (ET)(A) receptor, ET(B) receptor and M(3) muscarinic receptor were augmented, and the augmented contraction was most obvious in lobar bronchi. The order of efficacy of contraction for lobar bronchi induced by agonists was ET-1, sarafotoxin 6c>ACh>5-HT. OX8 (an antibody against CD8(+) T cells) strongly shifted and OX35 (an antibody against CD4(+) T cells) modestly shifted isoprenaline-induced concentration-relaxation curves in a nonparallel fashion to the left with an increased R(max) in asthmatic rats and sarafotoxin 6c-induced concentration-contractile curves to the right with a decreased E(max). CONCLUSION The inhibition of airway relaxation and the augmentation of contraction mediated by receptors contribute to airway hyperresponsiveness and involve CD8(+) and CD4(+) T cells.Acta Pharmacologica Sinica (2009) 30: 965-972; doi: 10.1038/aps.2009.61.
Collapse
|
28
|
Deng L, Bosse Y, Brown N, Chin LYM, Connolly SC, Fairbank NJ, King GG, Maksym GN, Paré PD, Seow CY, Stephen NL. Stress and strain in the contractile and cytoskeletal filaments of airway smooth muscle. Pulm Pharmacol Ther 2009; 22:407-16. [PMID: 19409505 DOI: 10.1016/j.pupt.2009.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 04/16/2009] [Accepted: 04/21/2009] [Indexed: 10/20/2022]
Abstract
Stress and strain are omnipresent in the lung due to constant lung volume fluctuation associated with respiration, and they modulate the phenotype and function of all cells residing in the airways including the airway smooth muscle (ASM) cell. There is ample evidence that the ASM cell is very sensitive to its physical environment, and can alter its structure and/or function accordingly, resulting in either desired or undesired consequences. The forces that are either conferred to the ASM cell due to external stretching or generated inside the cell must be borne and transmitted inside the cytoskeleton (CSK). Thus, maintaining appropriate levels of stress and strain within the CSK is essential for maintaining normal function. Despite the importance, the mechanisms regulating/dysregulating ASM cytoskeletal filaments in response to stress and strain remained poorly understood until only recently. For example, it is now understood that ASM length and force are dynamically regulated, and both can adapt over a wide range of length, rendering ASM one of the most malleable living tissues. The malleability reflects the CSK's dynamic mechanical properties and plasticity, both of which strongly interact with the loading on the CSK, and all together ultimately determines airway narrowing in pathology. Here we review the latest advances in our understanding of stress and strain in ASM cells, including the organization of contractile and cytoskeletal filaments, range and adaptation of functional length, structural and functional changes of the cell in response to mechanical perturbation, ASM tone as a mediator of strain-induced responses, and the novel glassy dynamic behaviors of the CSK in relation to asthma pathophysiology.
Collapse
Affiliation(s)
- Linhong Deng
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, and National 985 Project Institute of Biorheology and Gene Regulation, Bioengineering College, Chongqing University, Chongqing, China.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Krishnan R, Trepat X, Nguyen TTB, Lenormand G, Oliver M, Fredberg JJ. Airway smooth muscle and bronchospasm: fluctuating, fluidizing, freezing. Respir Physiol Neurobiol 2008; 163:17-24. [PMID: 18514592 PMCID: PMC2591927 DOI: 10.1016/j.resp.2008.04.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 04/08/2008] [Accepted: 04/10/2008] [Indexed: 11/24/2022]
Abstract
We review here four recent findings that have altered in a fundamental way our understanding of airways smooth muscle (ASM), its dynamic responses to physiological loading, and their dominant mechanical role in bronchospasm. These findings highlight ASM remodeling processes that are innately out-of-equilibrium and dynamic, and bring to the forefront a striking intersection between topics in condensed matter physics and ASM cytoskeletal biology. By doing so, they place in a new light the role of enhanced ASM mass in airway hyper-responsiveness as well as in the failure of a deep inspiration to relax the asthmatic airway. These findings have established that (i) ASM length is equilibrated dynamically, not statically; (ii) ASM dynamics closely resemble physical features exhibited by so-called soft glassy materials; (iii) static force-length relationships fail to describe dynamically contracted ASM states; (iv) stretch fluidizes the ASM cytoskeleton. Taken together, these observations suggest that at the origin of the bronchodilatory effect of a deep inspiration, and its failure in asthma, may lie glassy dynamics of the ASM cell.
Collapse
Affiliation(s)
- Ramaswamy Krishnan
- Program in Molecular and Integrative Physiological Sciences, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, United States
| | | | | | | | | | | |
Collapse
|
30
|
Oldenburg PJ, Wyatt TA, Factor PH, Sisson JH. Alcohol feeding blocks methacholine-induced airway responsiveness in mice. Am J Physiol Lung Cell Mol Physiol 2008; 296:L109-14. [PMID: 18931055 DOI: 10.1152/ajplung.00487.2007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Historical accounts of alcohol administration to patients with breathing problems suggest that alcohol may have bronchodilating properties. We hypothesized that acute alcohol exposure will alter airway responsiveness (AR) in mice. To test this hypothesis, C57BL/6 mice were fed either 20% alcohol in drinking water (fed) or received a single intraperitoneal (ip) injection of alcohol (3 g/kg). Control groups received regular drinking water or ip saline. AR was assessed by means of ventilation or barometric plethysmography and reported as either total lung resistance or enhanced pause for each group of mice. To confirm alcohol exposure, elevated blood alcohol levels were documented. Alcohol feeding significantly blocked methacholine-triggered AR compared with water-fed controls. Comparable blunting of AR was also accomplished through a single ip injection of alcohol when compared with saline-injected controls. The alcohol response was slowly reversible in both routes of administration after withdrawal of alcohol: AR attenuation by alcohol persisted 12-20 h (ip) or up to 2 wk (fed) after blood alcohol cleared consistent with a sustained bronchodilator effect. These data demonstrate that brief alcohol exposure blunts AR in this murine model of alcohol exposure suggesting a role for alcohol in the modulation of bronchial motor tone.
Collapse
Affiliation(s)
- P J Oldenburg
- Department of Internal Medicine, Pulmonary, Critical Care, Sleep, and Allergy Section, University of Nebraska Medical Center, Omaha, NE, USA
| | | | | | | |
Collapse
|
31
|
Abstract
A novel physical perspective of molecular interactions within the cytoskeleton of the airway smooth muscle cell may help to explain why the most efficacious of all known bronchodilatory agencies-a simple deep inspiration-becomes abrogated during the spontaneous asthma attack and leads thereby to excessive airway narrowing. This perspective invites us to think of airway smooth muscle not only biochemically as a nidus of traditional cell signaling and immune modulation or mechanically as a motor for generation of active forces but also physically as a phase of soft condensed matter that can restrict airway stretch and dilation. This is perhaps a risky path and is surely an unconventional one, but it is where the trail of evidence leads. This line of investigation is unlikely by itself to provide an asthma cure but will lead to a new conceptual framework without which novel pathways, unsuspected phase transitions, and unanticipated mechanisms of action of target molecules would almost surely remain hidden. Glassy dynamics of the cytoskeleton are likely to be important in a wide range of biological functions and disease processes, but had it not been for their preeminent role in bronchospasm, they might never have been discovered.
Collapse
|
32
|
Farghaly HSM, Blagbrough IS, Medina-Tato DA, Watson ML. Interleukin 13 increases contractility of murine tracheal smooth muscle by a phosphoinositide 3-kinase p110delta-dependent mechanism. Mol Pharmacol 2008; 73:1530-7. [PMID: 18276774 DOI: 10.1124/mol.108.045419] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Th2 cytokine interleukin (IL) 13 can elicit a number of responses consistent with a key role in the pathogenesis of asthma. We have used pharmacological and genetic approaches to demonstrate the role of signaling via the class I phosphoinositide 3-kinase p110delta isoform in IL-13-induced hyper-responsiveness of murine tracheal smooth muscle contractility in vitro. IL-13 treatment of tracheal tissue is associated with an early activation of phosphoinositide 3-kinase (PI3K), as assessed by phosphorylation of Akt. Tracheal smooth muscle contractility is enhanced by overnight incubation with IL-13, resulting in increased maximal contractions (E(max)) to carbachol (CCh) and KCl. Inhibition of PI3K by the non-isoform-selective inhibitors wortmannin or 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), or the selective inhibitor of the PI3K p110delta isoform 2-(6-aminopurin-9-ylmethyl)-5-methyl-3-O-tolyl-3H-quinazolin-4-one (IC87114), prevented IL-13-induced hyper-responsiveness. Consistent with a role for PI3K p110delta in IL-13-induced hyper-responsiveness, IL-13 was unable to induce hyper-responsiveness in tissues from mice expressing the catalytically inactive form of p110delta (p110delta(D910A)). These data indicate that IL-13 contributes to tracheal smooth muscle hyper-responsiveness via the PI3K p110delta isoform. In addition to previously reported effects on airway inflammation, inhibition of PI3K p110delta may be a useful target for the treatment of asthma by preventing IL-13-induced airway smooth muscle hyper-responsiveness.
Collapse
Affiliation(s)
- Hanan S M Farghaly
- Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK
| | | | | | | |
Collapse
|
33
|
Tomei AA, Choe MM, Swartz MA. Effects of dynamic compression on lentiviral transduction in an in vitro airway wall model. Am J Physiol Lung Cell Mol Physiol 2007; 294:L79-86. [PMID: 18024723 DOI: 10.1152/ajplung.00062.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asthmatic patients are more susceptible to viral infection, and we asked whether dynamic strain on the airway wall (such as that associated with bronchoconstriction) would influence the rate of viral infection of the epithelial and subepithelial cells. To address this, we characterized the barrier function of a three-dimensional culture model of the bronchial airway wall mucosa, modified the culture conditions for optimization of ciliogenesis, and compared epithelial and subepithelial green fluorescent protein (GFP) transduction by a pWpts-GFP lentivirus, pseudotyped with VSV-G, under static vs. dynamic conditions. The model consisted of human lung fibroblasts, bronchial epithelial cells, and a type I collagen matrix, and after 21 days of culture at air liquid interface, it exhibited a pseudostratified epithelium comprised of basal cells, mucus-secreting cells, and ciliated columnar cells with beating cilia. Microparticle tracking revealed partial coordination of mucociliary transport among groups of cells. Slow dynamic compression of the airway wall model (15% strain at 0.1 Hz over 3 days) substantially enhanced GFP transduction of epithelial cells and underlying fibroblasts. Fibroblast-only controls showed a similar degree of transduction enhancement when undergoing dynamic strain, suggesting enhanced transport through the matrix. Tight junction loss in the epithelium after mechanical stress was observed by immunostaining. We conclude that dynamic compressive strain such as that associated with bronchoconstriction may promote transepithelial transport and enhance viral transgene delivery to epithelial and subepithelial cells. This finding has significance for asthma pathophysiology as well as for designing delivery strategies of viral gene therapies to the airways.
Collapse
Affiliation(s)
- Alice A Tomei
- Institute of Bioengineering, SV-LMBM, Station 15, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | | | | |
Collapse
|
34
|
Mauad T, Bel EH, Sterk PJ. Asthma therapy and airway remodeling. J Allergy Clin Immunol 2007; 120:997-1009; quiz 1010-1. [PMID: 17681364 DOI: 10.1016/j.jaci.2007.06.031] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 06/20/2007] [Accepted: 06/22/2007] [Indexed: 12/13/2022]
Abstract
Asthma is characterized by variable degrees of chronic inflammation and structural alterations in the airways. The most prominent abnormalities include epithelial denudation, goblet cell metaplasia, subepithelial thickening, increased airway smooth muscle mass, bronchial gland enlargement, angiogenesis, and alterations in extracellular matrix components, involving large and small airways. Chronic inflammation is thought to initiate and perpetuate cycles of tissue injury and repair in asthma, although remodeling may also occur in parallel with inflammation. In the absence of definite evidence on how different remodeling features affect lung function in asthma, the working hypothesis should be that structural alterations can lead to the development of persistent airway hyperresponsiveness and fixed airway obstruction. It is still unanswered whether and when to begin treating patients with asthma to prevent or reverse deleterious remodeling, which components of remodeling to target, and how to monitor remodeling. Consequently, efforts are being made to understand better the effects of conventional anti-inflammatory therapies, such as glucocorticosteroids, on airway structural changes. Animal models, in vitro studies, and some clinical studies have advanced present knowledge on the cellular and molecular pathways involved in airway remodeling. This has encouraged the development of biologicals aimed to target various components of airway remodeling. Progress in this area requires the explicit linking of modern structure-function analysis with innovative biopharmaceutical approaches.
Collapse
Affiliation(s)
- Thais Mauad
- Department of Pathology, São Paulo University Medical School, São Paulo, Brazil
| | | | | |
Collapse
|
35
|
Frey U. Predicting asthma control and exacerbations: chronic asthma as a complex dynamic model. Curr Opin Allergy Clin Immunol 2007; 7:223-30. [PMID: 17489039 DOI: 10.1097/aci.0b013e32810fd771] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Predicting asthma episodes is notoriously difficult but has potentially significant consequences for the individual, as well as for healthcare services. The purpose of this review is to describe recent insights into the prediction of acute asthma episodes in relation to classical clinical, functional or inflammatory variables, as well as present a new concept for evaluating asthma as a dynamically regulated homeokinetic system. RECENT FINDINGS Risk prediction for asthma episodes or relapse has been attempted using clinical scoring systems, considerations of environmental factors and lung function, as well as inflammatory and immunological markers in induced sputum or exhaled air, and these are summarized here. We have recently proposed that newer mathematical methods derived from statistical physics may be used to understand the complexity of asthma as a homeokinetic, dynamic system consisting of a network comprising multiple components, and also to assess the risk for future asthma episodes based on fluctuation analysis of long time series of lung function. SUMMARY Apart from the classical analysis of risk factor and functional parameters, this new approach may be used to assess asthma control and treatment effects in the individual as well as in future research trials.
Collapse
Affiliation(s)
- Urs Frey
- Department of Paediatric Respiratory Medicine, University Children's Hospital of Berne, Inselspital, 3010 Berne, Switzerland.
| |
Collapse
|
36
|
Gil FR, Lauzon AM. Smooth muscle molecular mechanics in airway hyperresponsiveness and asthma. Can J Physiol Pharmacol 2007; 85:133-40. [PMID: 17487252 DOI: 10.1139/y06-096] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Asthma is a respiratory disorder characterized by airway inflammation and hyperresponsiveness associated with reversible airway obstruction. The relative contributions of airway hyperresponsiveness and inflammation are still debated, but ultimately, airway narrowing mediated by airway smooth muscle contraction is the final pathway to asthma. Considerable effort has been devoted towards identifying the factors that lead to the airway smooth muscle hypercontractility observed in asthma, and this will be the focus of this review. Airway remodeling has been observed in severe and fatal asthma. However, it is unclear whether remodeling plays a protective role or worsens airway responsiveness. Smooth muscle plasticity is a mechanism likely implicated in asthma, whereby contractile filament rearrangements lead to maximal force production, independent of muscle length. Increased smooth muscle rate of shortening via altered signaling pathways or altered contractile protein expression has been demonstrated in asthma and in numerous models of airway hyperresponsiveness. Increased rate of shortening is implicated in counteracting the relaxing effect of tidal breathing and deep inspirations, thereby creating a contracted airway smooth muscle steady-state. Further studies are therefore required to understand the numerous mechanisms leading to the airway hyperresponsiveness observed in asthma as well as their multiple interactions.
Collapse
Affiliation(s)
- Fulvio R Gil
- Meakins-Christie Laboratories, McGill University, 3626 St-Urbain Street, Montréal, QC H2X 2P2, Canada
| | | |
Collapse
|
37
|
An S, Bai T, Bates J, Black J, Brown R, Brusasco V, Chitano P, Deng L, Dowell M, Eidelman D, Fabry B, Fairbank N, Ford L, Fredberg J, Gerthoffer W, Gilbert S, Gosens R, Gunst S, Halayko A, Ingram R, Irvin C, James A, Janssen L, King G, Knight D, Lauzon A, Lakser O, Ludwig M, Lutchen K, Maksym G, Martin J, Mauad T, McParland B, Mijailovich S, Mitchell H, Mitchell R, Mitzner W, Murphy T, Paré P, Pellegrino R, Sanderson M, Schellenberg R, Seow C, Silveira P, Smith P, Solway J, Stephens N, Sterk P, Stewart A, Tang D, Tepper R, Tran T, Wang L. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma. Eur Respir J 2007; 29:834-60. [PMID: 17470619 PMCID: PMC2527453 DOI: 10.1183/09031936.00112606] [Citation(s) in RCA: 279] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Excessive airway obstruction is the cause of symptoms and abnormal lung function in asthma. As airway smooth muscle (ASM) is the effecter controlling airway calibre, it is suspected that dysfunction of ASM contributes to the pathophysiology of asthma. However, the precise role of ASM in the series of events leading to asthmatic symptoms is not clear. It is not certain whether, in asthma, there is a change in the intrinsic properties of ASM, a change in the structure and mechanical properties of the noncontractile components of the airway wall, or a change in the interdependence of the airway wall with the surrounding lung parenchyma. All these potential changes could result from acute or chronic airway inflammation and associated tissue repair and remodelling. Anti-inflammatory therapy, however, does not "cure" asthma, and airway hyperresponsiveness can persist in asthmatics, even in the absence of airway inflammation. This is perhaps because the therapy does not directly address a fundamental abnormality of asthma, that of exaggerated airway narrowing due to excessive shortening of ASM. In the present study, a central role for airway smooth muscle in the pathogenesis of airway hyperresponsiveness in asthma is explored.
Collapse
Affiliation(s)
- S.S. An
- Division of Physiology, Dept of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health
| | - T.R. Bai
- James Hogg iCAPTURE Centre, University of British Columbia, Vancouver
| | - J.H.T. Bates
- Vermont Lung Center, University of Vermont College of Medicine, Burlington, VT
| | - J.L. Black
- Dept of Pharmacology, University of Sydney, Sydney
| | - R.H. Brown
- Dept of Anesthesiology and Critical Care medicine, Johns Hopkins Medical Institutions, Baltimore, MD
| | - V. Brusasco
- Dept of Internal Medicine, University of Genoa, Genoa
| | - P. Chitano
- Dept of Paediatrics, Duke University Medical Center, Durham, NC
| | - L. Deng
- Program in Molecular and Integrative Physiological Sciences, Dept of Environmental Health, Harvard School of Public Health
- Bioengineering College, Chongqing University, Chongqing, China
| | - M. Dowell
- Section of Pulmonary and Critical Care Medicine
| | - D.H. Eidelman
- Meakins-Christie Laboratories, Dept of Medicine, McGill University, Montreal
| | - B. Fabry
- Center for Medical Physics and Technology, Erlangen, Germany
| | - N.J. Fairbank
- School of Biomedical Engineering, Dalhousie University, Halifax
| | | | - J.J. Fredberg
- Program in Molecular and Integrative Physiological Sciences, Dept of Environmental Health, Harvard School of Public Health
| | - W.T. Gerthoffer
- Dept of Pharmacology, University of Nevada School of Medicine, Reno, NV
| | | | - R. Gosens
- Dept of Physiology, University of Manitoba, Winnipeg
| | - S.J. Gunst
- Dept of Physiology, Indiana University School of Medicine, Indianapolis, IN
| | - A.J. Halayko
- Dept of Physiology, University of Manitoba, Winnipeg
| | - R.H. Ingram
- Dept of Medicine, Emory University School of Medicine, Atlanta, GA
| | - C.G. Irvin
- Vermont Lung Center, University of Vermont College of Medicine, Burlington, VT
| | - A.L. James
- West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands
| | - L.J. Janssen
- Dept of Medicine, McMaster University, Hamilton, Canada
| | - G.G. King
- Woolcock Institute of Medical Research, Camperdown
| | - D.A. Knight
- James Hogg iCAPTURE Centre, University of British Columbia, Vancouver
| | - A.M. Lauzon
- Meakins-Christie Laboratories, Dept of Medicine, McGill University, Montreal
| | - O.J. Lakser
- Section of Paediatric Pulmonary Medicine, University of Chicago, Chicago, IL
| | - M.S. Ludwig
- Meakins-Christie Laboratories, Dept of Medicine, McGill University, Montreal
| | - K.R. Lutchen
- Dept of Biomedical Engineering, Boston University, Boston
| | - G.N. Maksym
- School of Biomedical Engineering, Dalhousie University, Halifax
| | - J.G. Martin
- Meakins-Christie Laboratories, Dept of Medicine, McGill University, Montreal
| | - T. Mauad
- Dept of Pathology, Sao Paulo University Medical School, Sao Paulo, Brazil
| | | | - S.M. Mijailovich
- Program in Molecular and Integrative Physiological Sciences, Dept of Environmental Health, Harvard School of Public Health
| | - H.W. Mitchell
- Discipline of Physiology, School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Perth
| | | | - W. Mitzner
- Division of Physiology, Dept of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health
| | - T.M. Murphy
- Dept of Paediatrics, Duke University Medical Center, Durham, NC
| | - P.D. Paré
- James Hogg iCAPTURE Centre, University of British Columbia, Vancouver
| | - R. Pellegrino
- Dept of Respiratory Physiopathology, S. Croce e Carle Hospital, Cuneo, Italy
| | - M.J. Sanderson
- Dept of Physiology, University of Massachusetts Medical School, Worcester, MA
| | - R.R. Schellenberg
- James Hogg iCAPTURE Centre, University of British Columbia, Vancouver
| | - C.Y. Seow
- James Hogg iCAPTURE Centre, University of British Columbia, Vancouver
| | - P.S.P. Silveira
- Dept of Pathology, Sao Paulo University Medical School, Sao Paulo, Brazil
| | - P.G. Smith
- Dept of Paediatrics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - J. Solway
- Section of Pulmonary and Critical Care Medicine
| | - N.L. Stephens
- Dept of Physiology, University of Manitoba, Winnipeg
| | - P.J. Sterk
- Dept of Pulmonology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A.G. Stewart
- Dept of Pharmacology, University of Melbourne, Parkville, Australia
| | - D.D. Tang
- Center for Cardiovascular Sciences, Albany Medical College, Albany, NY, USA
| | - R.S. Tepper
- Dept of Paediatrics, Indiana University School of Medicine, Indianapolis, IN
| | - T. Tran
- Dept of Physiology, University of Manitoba, Winnipeg
| | - L. Wang
- Dept of Paediatrics, Duke University Medical Center, Durham, NC
| |
Collapse
|
38
|
Oliver MN, Fabry B, Marinkovic A, Mijailovich SM, Butler JP, Fredberg JJ. Airway hyperresponsiveness, remodeling, and smooth muscle mass: right answer, wrong reason? Am J Respir Cell Mol Biol 2007; 37:264-72. [PMID: 17463392 PMCID: PMC1994228 DOI: 10.1165/rcmb.2006-0418oc] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We quantified the effects of airway wall remodeling upon airway smooth muscle (ASM) shortening. Isolated ASM from sheep was attached to a servo-controller that applied a physiologic load. This load could be altered to reflect specified changes of airway wall geometry, elasticity, parenchymal tethering, transpulmonary pressure (P(L)), and fluctuations in P(L) associated with breathing. Starting at a reference length (L(ref)), ASM was stimulated with acetlycholine and held at constant P(L) of 4 cm H(2)O for 2 h. When all compartments were thickened to simulate the asthmatic airway but P(L) was held fixed, ASM shortened much more than that in the normal airway (to 0.52 L(ref) versus 0.66 L(ref)). When breathing with deep inspirations (DIs) was initiated, within the first three DIs the ASM in the normal airway lengthened to 0.84 L(ref), whereas that in the asthmatic airway remained stuck at 0.53 L(ref). Thickening of the smooth muscle layer alone produced the greatest muscle shortening (to 0.47 L(ref)) when compared with thickening of only submucosal (to 0.67 L(ref)) or only adventitial (to 0.62 L(ref)) compartments. With increased ASM mass, the ASM failed to lengthen in response to DIs, whereas in the airway with thickened submucosal and adventitial layers ASM lengthened dramatically (to 0.83 L(ref)). These findings confirm the long-held conclusion that increased muscle mass is the functionally dominant derangement, but mechanisms accounting for this conclusion differ dramatically from those previously presumed. Furthermore, increased ASM mass explained both hyperresponsiveness and the failure of a DI to relax the asthmatic airway.
Collapse
Affiliation(s)
- Madavi N Oliver
- Physiology Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
| | | | | | | | | | | |
Collapse
|
39
|
Chanez P, Wenzel SE, Anderson GP, Anto JM, Bel EH, Boulet LP, Brightling CE, Busse WW, Castro M, Dahlen B, Dahlen SE, Fabbri LM, Holgate ST, Humbert M, Gaga M, Joos GF, Levy B, Rabe KF, Sterk PJ, Wilson SJ, Vachier I. Severe asthma in adults: what are the important questions? J Allergy Clin Immunol 2007; 119:1337-48. [PMID: 17416409 DOI: 10.1016/j.jaci.2006.11.702] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 11/10/2006] [Accepted: 11/15/2006] [Indexed: 12/18/2022]
Abstract
The term severe refractory asthma (SRA) in adults applies to patients who remain difficult to control despite extensive re-evaluation of diagnosis and management following an observational period of at least 6 months by a specialist. Factors that influence asthma control should be recognized and adequately addressed prior to confirming the diagnosis of SRA. This report presents statements according to the literature defining SRA in order address the important questions. Phenotyping SRA will improve our understanding of mechanisms, natural history, and prognosis. Female gender, obesity, and smoking are associated with SRA. Atopy is less frequent in SRA, but occupational sensitizers are common inducers of new-onset SRA. Viruses contribute to severe exacerbations and can persist in the airways for long periods. Inflammatory cells are in the airways of the majority of patients with SRA and persist despite steroid therapy. The T(H)2 immune process alone is inadequate to explain SRA. Reduced responsiveness to corticosteroids is common, and epithelial cell and smooth muscle abnormalities are found, contributing to airway narrowing. Large and small airway wall thickening is observed, but parenchymal abnormalities may influence airway limitation. Inhaled corticosteroids and bronchodilators are the mainstay of treatment, but patients with SRA remain uncontrolled, indicating a need for new therapies.
Collapse
Affiliation(s)
- Pascal Chanez
- INSERM U454 and Clinique des Maladies Respiratoires, Montpellier, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Lundblad LKA, Thompson-Figueroa J, Allen GB, Rinaldi L, Norton RJ, Irvin CG, Bates JHT. Airway hyperresponsiveness in allergically inflamed mice: the role of airway closure. Am J Respir Crit Care Med 2007; 175:768-74. [PMID: 17255559 PMCID: PMC1899295 DOI: 10.1164/rccm.200610-1410oc] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Allergically inflamed mice exhibit airway hyperresponsiveness to inhaled methacholine, which computer simulations of lung impedance suggest is due to enhanced lung derecruitment and which we sought to verify in the present study. METHODS BALB/c mice were sensitized and challenged with ovalbumin to induce allergic inflammation; the control mice were sensitized but received no challenge. The mice were then challenged with inhaled methacholine and respiratory system impedance tracked for the following 10 minutes. Respiratory elastance (H) was estimated from each impedance measurement. One group of mice was ventilated with 100% O(2) during this procedure and another group was ventilated with air. After the procedure, the mice were killed and ventilated with pure N(2), after which the trachea was tied off and the lungs were imaged with micro-computed tomography (micro-CT). RESULTS H was significantly higher in allergic mice than in control animals after methacholine challenge. The ratio of H at the end of the measurement period between allergic and nonallergic mice ventilated with O(2) was 1.36, indicating substantial derecruitment in the allergic animals. The ratio between lung volumes determined by micro-CT in the control and the allergic mice was also 1.36, indicative of a corresponding volume loss due to absorption atelectasis. Micro-CT images and histograms of Hounsfield units from the lungs also showed increased volume loss in the allergic mice compared with control animals after methacholine challenge. CONCLUSIONS These results support the conclusion that airway closure is a major component of hyperresponsiveness in allergically inflamed mice.
Collapse
Affiliation(s)
- Lennart K A Lundblad
- Vermont Lung Center, The University of Vermont College of Medicine, HSRF 230, 149 Beaumont Avenue, Burlington, VT 05405-0075, USA.
| | | | | | | | | | | | | |
Collapse
|
41
|
Slats AM, Sont JK, van Klink RHCJ, Bel EHD, Sterk PJ. Improvement in bronchodilation following deep inspiration after a course of high-dose oral prednisone in asthma. Chest 2006; 130:58-65. [PMID: 16840383 DOI: 10.1378/chest.130.1.58] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Bronchodilation following deep inspiration is usually impaired in patients with asthma. This might be due to changes in airway mechanics in the presence of inflammation or structural changes within the airways. Although inhaled corticosteroid treatment has been shown to improve airway responses to deep inspiration in patients with asthma, airway inflammation can persist despite inhaled corticosteroid treatment, and thus could still influence the airway mechanics during deep breaths. We hypothesized that oral steroid treatment further optimizes deep inspiration-induced bronchodilation in clinically stable asthmatic patients who are receiving therapy with inhaled corticosteroids. METHODS Twenty-four atopic patients with mild-to-moderate persistent asthma (FEV1, > 70% predicted; provocative concentration of methacholine causing a 20% fall in FEV1 [PC20], < 8 mg/mL), who were treated with 250 to 2,000 mug of beclomethasone-dipropionate or equivalent, participated in a parallel-design, double-blind study. Before and after treatment with 0.5 mg/kg/d prednisone or placebo for 14 days, a methacholine challenge was performed. Deep inspiration-induced bronchodilation was measured by the ratio of flow at 40% of FVC on the flow-volume curve after maximal inspiration/flow at 40% of FVC on the flow-volume curve after partial (60% of FVC) inspiration (M/P ratio). RESULTS The M/P ratio significantly increased from a mean of 1.31 (range, 1.0 to 1.7) to 1.49 (range, 1.1 to 2.3) in the prednisone group. Interestingly, the improvement in the M/P ratio did not correlate with an accompanying significant increase in PC20 for methacholine (mean change, 1.02; SD doubling dose, 0.97) and a decrease in exhaled nitric oxide (mean change, 14 parts per billion [ppb]; SD, 33.4 ppb). CONCLUSIONS Systemic antiinflammatory treatment in addition to maintenance therapy with inhaled corticosteroids increases bronchodilation by deep inspiration in patients with mild-to-moderate persistent asthma. This suggests that residual inflammation impairs airway mechanics in asthma patients.
Collapse
Affiliation(s)
- Annelies M Slats
- Department of Pulmonology (C2-P-62), Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | | | | | | | | |
Collapse
|
42
|
|
43
|
Abstract
Airways are embedded in the mechanically dynamic environment of the lung. In utero, this mechanical environment is defined largely by fluid secretion into the developing airway lumen. Clinical, whole lung, and cellular studies demonstrate pivotal roles for mechanical distention in airway morphogenesis and cellular behavior during lung development. In the adult lung, the mechanical environment is defined by a dynamic balance of surface, tissue, and muscle forces. Diseases of the airways modulate both the mechanical stresses to which the airways are exposed as well as the structure and mechanical behavior of the airways. For instance, in asthma, activation of airway smooth muscle abruptly changes the airway size and stress state within the airway wall; asthma also results in profound remodeling of the airway wall. Data now demonstrate that airway epithelial cells, smooth muscle cells, and fibroblasts respond to their mechanical environment. A prominent role has been identified for the epithelium in transducing mechanical stresses, and in both the fetal and mature airways, epithelial cells interact with mesenchymal cells to coordinate remodeling of tissue architecture in response to the mechanical environment.
Collapse
Affiliation(s)
- Daniel J Tschumperlin
- Physiology Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
| | | |
Collapse
|
44
|
Choe MM, Sporn PHS, Swartz MA. Extracellular matrix remodeling by dynamic strain in a three-dimensional tissue-engineered human airway wall model. Am J Respir Cell Mol Biol 2006; 35:306-13. [PMID: 16601241 PMCID: PMC2643283 DOI: 10.1165/rcmb.2005-0443oc] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Airway wall remodeling is a hallmark of asthma, characterized by subepithelial thickening and extracellular matrix (ECM) remodeling. Mechanical stress due to hyperresponsive smooth muscle cells may contribute to this remodeling, but its relevance in a three-dimensional environment (where the ECM plays an important role in modulating stresses felt by cells) is unclear. To characterize the effects of dynamic compression in ECM remodeling in a physiologically relevant three-dimensional environment, a tissue-engineered human airway wall model with differentiated bronchial epithelial cells atop a collagen gel containing lung fibroblasts was used. Lateral compressive strain of 10 or 30% at 1 or 60 cycles per hour was applied using a novel straining device. ECM remodeling was assessed by immunohistochemistry and zymography. Dynamic strain, particularly at the lower magnitude, induced airway wall remodeling, as indicated by increased deposition of types III and IV collagen and increased secretion of matrix metalloproteinase-2 and -9. These changes paralleled increased myofibroblast differentiation and were fibroblast-dependent. Furthermore, the spatial pattern of type III collagen deposition correlated with that of myofibroblasts; both were concentrated near the epithelium and decreased diffusely away from the surface, indicating some epithelial control of the remodeling response. Thus, in a physiologically relevant three-dimensional model of the bronchial wall, dynamic compressive strain induced tissue remodeling that mimics many features of remodeling seen in asthma, in the absence of inflammation and dependent on epithelial-fibroblast signaling.
Collapse
Affiliation(s)
- Melanie M Choe
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA
| | | | | |
Collapse
|
45
|
Maksym GN, Deng L, Fairbank NJ, Lall CA, Connolly SC. Beneficial and harmful effects of oscillatory mechanical strain on airway smooth muscle. Can J Physiol Pharmacol 2006; 83:913-22. [PMID: 16333363 DOI: 10.1139/y05-091] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Airway smooth muscle (ASM) cells are constantly under mechanical strain as the lung cyclically expands and deflates, and this stretch is now known to modulate the contractile function of ASM. However, depending on the experimental conditions, stretch is either beneficial or harmful limiting or enhancing contractile force generation, respectively. Stretch caused by a deep inspiration is known to be beneficial in limiting or reversing airway constriction in healthy individuals, and oscillatory stretch lowers contractile force and stiffness or lengthens muscle in excised airway tissue strips. Stretch in ASM culture has generally been reported to cause increased contractile function through increases in proliferation, contractile protein content, and organization of the cell cytoskeleton. Recent evidence indicates the type of stretch is critically important. Growing cells on flexible membranes where stretch is non-uniform and anisotropic leads to pro-contractile changes, whereas uniform biaxial stretch causes the opposite effects. Furthermore, the role of contractile tone might be important in modulating the response to mechanical stretch in cultured cells. This report will review the contrasting evidence for modulation of contractile function of ASM, both in vivo and in vitro, and summarize the recent evidence that mechanical stress applied either acutely within 2 h or chronically over 11 d is a potent stimulus for cytoskeletal remodelling and stiffening. We will also point to new data suggesting that perhaps some of the difference in response to stretch might lie with one of the fundamental differences in the ASM environment in asthma and in culture--the presence of elevated contractile tone.
Collapse
Affiliation(s)
- Geoffrey N Maksym
- School of Biomedical Engineering, Dalhousie University, Halifax, NS B3H 1W2, Canada.
| | | | | | | | | |
Collapse
|
46
|
Silveira PSP, Fredberg JJ. Smooth muscle length adaptation and actin filament length: a network model of the cytoskeletal dysregulation. Can J Physiol Pharmacol 2006; 83:923-31. [PMID: 16333364 DOI: 10.1139/y05-092] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Length adaptation of the airway smooth muscle cell is attributable to cytoskeletal remodeling. It has been proposed that dysregulated actin filaments may become longer in asthma, and that such elongation would prevent a parallel-to-series transition of contractile units, thus precluding the well-known beneficial effects of deep inspirations and tidal breathing. To test the potential effect that actin filament elongation could have in overall muscle mechanics, we present an extremely simple model. The cytoskeleton is represented as a 2-D network of links (contractile filaments) connecting nodes (adhesion plaques). Such a network evolves in discrete time steps by forming and dissolving links in a stochastic fashion. Links are formed by idealized contractile units whose properties are either those from normal or elongated actin filaments. Oscillations were then imposed on the network to evaluate both the effects of breathing and length adaptation. In response to length oscillation, a network with longer actin filaments showed smaller decreases of force, smaller increases in compliance, and higher shortening velocities. Taken together, these changes correspond to a network that is refractory to the effects of breathing and therefore approximates an asthmatic scenario. Thus, an extremely simple model seems to capture some relatively complex mechanics of airway smooth muscle, supporting the idea that dysregulation of actin filament length may contribute to excessive airway narrowing.
Collapse
Affiliation(s)
- Paulo S P Silveira
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA.
| | | |
Collapse
|
47
|
Chen B, Liu G, Shardonofsky F, Dowell M, Lakser O, Mitchell RW, Fredberg JJ, Pinto LH, Solway J. Tidal breathing pattern differentially antagonizes bronchoconstriction in C57BL/6J vs. A/J mice. J Appl Physiol (1985) 2006; 101:249-55. [PMID: 16484363 DOI: 10.1152/japplphysiol.01010.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
There is abundant evidence that tidal breathing, and especially tidal breathing at elevated minute ventilation, antagonizes the development and persistence of airflow obstruction during bronchoconstrictor stimulation in normal animals and people. Here, we studied the antiobstructive effect of different tidal breathing patterns in C57Bl/6J and A/J mice during bronchoconstriction induced by continuous or bolus infusion of methacholine. Anesthetized, paralyzed mice were mechanically ventilated at 1,500 ml.kg(-1).min(-1), using each of three breathing patterns: 5 ml/kg, 300 breath/min; 10 ml/kg, 150 breath/min; or 20 ml/kg, 75 breath/min. Changing from 10 ml/kg, 150 breath/min to 20 ml/kg, 75 breath/min, breathing functionally antagonized bronchoconstriction, reducing the level of airflow obstruction induced by methacholine infusion or boluses equivalently in both strains. In marked contrast, changing from 10 ml/kg, 150 breath/min to 5 ml/kg, 300 breath/min, breathing substantially exacerbated methacholine-induced airflow obstruction in A/J mice, whereas it had no significant effect in C57Bl/6J mice. Our results therefore demonstrate that 1) even at moderate, fixed minute ventilation, the precise breathing pattern can influence the degree of airflow obstruction substantially, and 2) the influence of breathing pattern on bronchoconstriction differs considerably between genetically diverse inbred mouse strains. These findings imply that differences in antiobstructive effects of breathing can contribute to differences in apparent airway constrictor responsiveness. Much attention has been placed on dysregulation of contractile function of airway smooth muscle in human disease. We suggest that important pathophysiology might also be found in impairment of the functional antagonist effect of tidal breathing on airflow obstruction.
Collapse
Affiliation(s)
- Bohao Chen
- Section of Pulmonary and Critical Care Medicine, University of Chicago, 5841 S. Maryland Ave., MC6026, Chicago, Illinois 60637, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
An SS, Fabry B, Trepat X, Wang N, Fredberg JJ. Do biophysical properties of the airway smooth muscle in culture predict airway hyperresponsiveness? Am J Respir Cell Mol Biol 2006; 35:55-64. [PMID: 16484685 PMCID: PMC2553364 DOI: 10.1165/rcmb.2005-0453oc] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Airway hyperresponsiveness is a cardinal feature of asthma but remains largely unexplained. In asthma, the key end-effector of acute airway narrowing is the airway smooth muscle (ASM) cell. Here we report novel biophysical properties of the ASM cell isolated from the relatively hyporesponsive Lewis rat versus the relatively hyperresponsive Fisher rat. We focused upon the ability of the cytoskeleton (CSK) of the ASM cell to stiffen, to generate contractile forces, and to remodel. We used optical magnetic twisting cytometry to measure cell stiffness and traction microscopy to measure contractile forces. To measure remodeling dynamics, we quantified spontaneous nanoscale motions of a microbead tightly anchored to the CSK. In response to a panel of contractile and relaxing agonists, Fisher ASM cells showed greater stiffening, bigger contractile forces, and faster CSK remodeling; they also exhibited higher effective temperature of the CSK matrix. These physical differences measured at the level of the single cell in vitro were consistent with strain-related differences in airway responsiveness in vivo. As such, comprehensive biophysical characterizations of CSK dynamics at the level of the cell in culture may provide novel perspectives on the ASM and its contributions to the excessive airway narrowing in asthma.
Collapse
Affiliation(s)
- Steven S An
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
| | | | | | | | | |
Collapse
|
49
|
Hinton M, Mellow L, Halayko AJ, Gutsol A, Dakshinamurti S. Hypoxia induces hypersensitivity and hyperreactivity to thromboxane receptor agonist in neonatal pulmonary arterial myocytes. Am J Physiol Lung Cell Mol Physiol 2005; 290:L375-84. [PMID: 16214814 DOI: 10.1152/ajplung.00307.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PPHN, caused by perinatal hypoxia or inflammation, is characterized by an increased thromboxane-prostacyclin ratio and pulmonary vasoconstriction. We examined effects of hypoxia on myocyte thromboxane responsiveness. Myocytes from 3rd-6th generation pulmonary arteries of newborn piglets were grown to confluence and synchronized in contractile phenotype by serum deprivation. On the final 3 days of culture, myocytes were exposed to 10% O2 for 3 days; control myocytes from normoxic piglets were cultured in 21% O2. PPHN was induced in newborn piglets by 3-day hypoxic exposure (Fi(O2) 0.10); pulmonary arterial myocytes from these animals were maintained in normoxia. Ca2+ mobilization to thromboxane mimetic U-46619 and ATP was quantified using fura-2 AM. Three-day hypoxic exposure in vitro results in increased basal [Ca2+]i, faster and heightened peak Ca2+ response, and decreased U-46619 EC50. These functional changes persist in myocytes exposed to hypoxia in vivo but cultured in 21% O2. Blockade of Ca2+ entry and store refilling do not alter peak U-46619 Ca2+ responses in hypoxic or normoxic myocytes. Blockade of ryanodine-sensitive or IP3-gated intracellular Ca2+ channels inhibits hypoxic augmentation of peak U-46619 response. Ca2+ response to ryanodine alone is undetectable; ATP-induced Ca2+ mobilization is unaltered by hypoxia, suggesting no independent increase in ryanodine-sensitive or IP3-linked intracellular Ca2+ pool mobilization. We conclude hypoxia has a priming effect on neonatal pulmonary arterial myocytes, resulting in increased resting Ca2+, thromboxane hypersensitivity, and hyperreactivity. We postulate that hypoxia increases agonist-induced TP-R-linked IP3 pathway activation. Myocyte thromboxane hyperresponsiveness persists in culture after removal from the initiating hypoxic stimulus, suggesting altered gene expression.
Collapse
Affiliation(s)
- M Hinton
- Department of Physiology, University of Manitoba, and Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Canada R3A 1R9
| | | | | | | | | |
Collapse
|
50
|
Silveira PSP, Butler JP, Fredberg JJ. Length adaptation of airway smooth muscle: a stochastic model of cytoskeletal dynamics. J Appl Physiol (1985) 2005; 99:2087-98. [PMID: 16081628 DOI: 10.1152/japplphysiol.00159.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
To account for cytoskeleton remodeling as well as smooth muscle length adaptation, here we represent the cytoskeleton as a two-dimensional network of links (contractile filaments or stress fibers) that connect nodes (dense plaques or focal adhesions). The network evolves in continuous turnover with probabilities of link formation and dissolution. The probability of link formation increases with the available fraction of contractile units, increases with the degree of network activation, and decreases with increasing distance between nodes, d, as 1/d(s), where s controls the distribution of link lengths. The probability of link dissolution decays with time to mimic progressive cytoskeleton stabilization. We computed network force (F) as the vector summation of link forces exerted at all nodes, unloaded shortening velocity (V) as being proportional to the average link length, and network compliance (C) as the change in network length per change in elastic force. Imposed deformation caused F to decrease transiently and then recover dynamically; recovery ability decreased with increasing time after activation, mimicking observed biological behavior. Isometric contractions showed small sensitivity of F to network length, thus maintaining high force over a wide range of lengths; V and C increased with increasing length. In these behaviors, link length regulation, as described by the parameter s, was found to be crucial. Concerning length adaptation, all phenomena reported thus far in the literature were captured by this extremely simple network model.
Collapse
Affiliation(s)
- Paulo S P Silveira
- Harvard School of Public Health, Department of Environmental Health, Boston, MA 02115, USA.
| | | | | |
Collapse
|