scholarly journals LOXL2 Mediates Airway Smooth Muscle Cell Matrix Stiffness and Drives Asthmatic Airway Remodelling

2020 ◽  
Author(s):  
Jopeth Ramis ◽  
Robert Middlewick ◽  
Francesco Pappalardo ◽  
Jennifer T. Cairns ◽  
Iain D. Stewart ◽  
...  

AbstractAirway smooth muscle cells (ASM) are fundamental to asthma pathogenesis, influencing bronchoconstriction, airway hyper-responsiveness, and airway remodelling. Extracellular matrix (ECM) can influence tissue remodelling pathways, however, to date no study has investigated the effect of ASM ECM stiffness and crosslinking on the development of asthmatic airway remodelling. We hypothesised that TGFβ activation by ASM is influenced by ECM in asthma and sought to investigate the mechanisms involved.This study combines in vitro and in vivo approaches: human ASM cells were used in vitro to investigate basal TGFβ activation and expression of ECM crosslinking enzymes. Human bronchial biopsies from asthmatic and non-asthmatic donors were used to confirm LOXL2 expression ASM. A chronic ovalbumin model of asthma was used to study the effect of LOXL2 inhibition on airway remodelling.We found that ASM cells from asthmatics activated more TGFβ basally than non-asthmatic controls and that diseased cell-derived ECM influences levels of TGFβ activated. Our data demonstrate that the ECM crosslinking enzyme LOXL2 is increased in asthmatic ASM cells and in bronchial biopsies. Crucially, we show that LOXL2 inhibition reduces ECM stiffness and TGFβ activation in vitro, and can reduce subepithelial collagen deposition and ASM thickness, two features of airway remodelling, in an ovalbumin mouse model of asthma.These data are the first to highlight a role for LOXL2 in the development of asthmatic airway remodelling and suggest that LOXL2 inhibition warrants further investigation as a potential therapy to reduce remodelling of the airways in severe asthma.

2022 ◽  
pp. 2004361
Author(s):  
Jopeth Ramis ◽  
Robert Middlewick ◽  
Francesco Pappalardo ◽  
Jennifer T. Cairns ◽  
Iain D. Stewart ◽  
...  

Airway smooth muscle cells (ASM) are fundamental to asthma pathogenesis, influencing bronchoconstriction, airway hyper-responsiveness, and airway remodelling. Extracellular matrix (ECM) can influence tissue remodelling pathways, however, to date no study has investigated the effect of ASM ECM stiffness and crosslinking on the development of asthmatic airway remodelling. We hypothesised that TGFβ activation by ASM is influenced by ECM in asthma and sought to investigate the mechanisms involved. This study combines in vitro and in vivo approaches: human ASM cells were used in vitro to investigate basal TGFβ activation and expression of ECM crosslinking enzymes. Human bronchial biopsies from asthmatic and non-asthmatic donors were used to confirm LOXL2 expression ASM. A chronic ovalbumin model of asthma was used to study the effect of LOXL2 inhibition on airway remodelling. We found that ASM cells from asthmatics activated more TGFβ basally than non-asthmatic controls and that diseased cell-derived ECM influences levels of TGFβ activated. Our data demonstrate that the ECM crosslinking enzyme LOXL2 is increased in asthmatic ASM cells and in bronchial biopsies. Crucially, we show that LOXL2 inhibition reduces ECM stiffness and TGFβ activation in vitro, and can reduce subepithelial collagen deposition and ASM thickness, two features of airway remodelling, in an ovalbumin mouse model of asthma. These data are the first to highlight a role for LOXL2 in the development of asthmatic airway remodelling and suggest that LOXL2 inhibition warrants further investigation as a potential therapy to reduce remodelling of the airways in severe asthma.


2013 ◽  
Vol 32 (3) ◽  
pp. 629-636 ◽  
Author(s):  
XIN ZENG ◽  
YING CHENG ◽  
YUEJUN QU ◽  
JIDE XU ◽  
ZHIYUAN HAN ◽  
...  

2011 ◽  
Vol 300 (6) ◽  
pp. L958-L966 ◽  
Author(s):  
Paul-André Risse ◽  
Taisuke Jo ◽  
Fernando Suarez ◽  
Nobuaki Hirota ◽  
Barbara Tolloczko ◽  
...  

IL-13 is an important mediator of allergen-induced airway hyperresponsiveness. This Th2 cytokine, produced by activated T cells, mast cells, and basophils, has been described to mediate a part of its effects independently of inflammation through a direct modulation of the airway smooth muscle (ASM). Previous studies demonstrated that IL-13 induces hyperresponsiveness in vivo and enhances calcium signaling in response to contractile agonists in vitro. We hypothesized that IL-13 drives human ASM cells (ASMC) to a procontractile phenotype. We evaluated ASM phenotype through the ability of the cell to proliferate, to contract, and to express contractile protein in response to IL-13. We found that IL-13 inhibits human ASMC proliferation (expression of Ki67 and bromodeoxyuridine incorporation) in response to serum, increasing the number of cells in G0/G1 phase and decreasing the number of cells in G2/M phases of the cell cycle. IL-13-induced inhibition of proliferation was not dependent on signal transducer and activator of transcription-6 but was IL-13Rα2 receptor dependent and associated with a decrease of Kruppel-like factor 5 expression. In parallel, IL-13 increased calcium signaling and the stiffening of human ASMC in response to 1 μM histamine, whereas the stiffening response to 30 mM KCl was unchanged. However, Western blot analysis showed unchanged levels of calponin, smooth muscle α-actin, vinculin, and myosin. We conclude that IL-13 inhibits proliferation via the IL-13Rα2 receptor and induces hypercontractility of human ASMC without change of the phenotypic markers of contractility.


2006 ◽  
Vol 291 (3) ◽  
pp. L312-L321 ◽  
Author(s):  
Abdelilah Soussi Gounni

The airway smooth muscle (ASM) has been typically described as a contractile tissue, responding to neurotransmitters and inflammatory mediators. However, it has recently been recognized that ASM cells can also secrete cytokines and chemokines and express cell adhesion molecules that are important for the perpetuation and modulation of airway inflammation. Recent progress has revealed the importance of IgE Fc receptors in stimulating and modulating the function of these cells. In particular, the high-affinity receptor for IgE (FcεRI) has been identified in primary human ASM cells in vitro and in vivo within bronchial biopsies of atopic asthmatic individuals. Moreover, activation of this receptor has been found to induce marked increases in the intracellular calcium concentrations and T helper 2 cytokines and chemokines release. This and other evidence discussed in this review provide an emerging view of FcεR/IgE network as a critical modulator of ASM cell function in allergic asthma.


2012 ◽  
Vol 302 (3) ◽  
pp. L325-L333 ◽  
Author(s):  
Yukikazu Ichimaru ◽  
David I. Krimmer ◽  
Janette K. Burgess ◽  
Judith L. Black ◽  
Brian G. G. Oliver

Chronic obstructive pulmonary disease (COPD) and asthma are characterized by irreversible remodeling of the airway walls, including thickening of the airway smooth muscle layer. Perlecan is a large, multidomain, proteoglycan that is expressed in the lungs, and in other organ systems, and has been described to have a role in cell adhesion, angiogenesis, and proliferation. This study aimed to investigate functional properties of the different perlecan domains in relation to airway smooth muscle cells (ASMC). Primary human ASMC obtained from donors with asthma ( n = 13), COPD ( n = 12), or other lung disease ( n = 20) were stimulated in vitro with 1 ng/ml transforming growth factor-β1 (TGF-β1) before perlecan deposition and cytokine release were analyzed. In some experiments, inhibitors of signaling molecules were added. Perlecan domains I–V were seeded on tissue culture plates at 10 μg/ml with 1 μg/ml collagen I as a control. ASM was incubated on top of the peptides before being analyzed for attachment, proliferation, and wound healing. TGF-β1 upregulated deposition of perlecan by ASMC from COPD subjects only. TGF-β1 upregulated release of IL-6 into the supernatant of ASMC from all subjects. Inhibitors of SMAD and JNK signaling molecules decreased TGF-β1-induced perlecan deposition by COPD ASMC. Attachment of COPD ASMC was upregulated by collagen I and perlecan domains IV and V, while perlecan domain II upregulated attachment only of asthmatic ASMC. Seeding on perlecan domains did not increase proliferation of any ASMC type. TGF-β1-induced perlecan deposition may enhance attachment of migrating ASMC in vivo and thus may be a mechanism for ASMC layer hypertrophy in COPD.


Thorax ◽  
2010 ◽  
Vol 65 (Suppl 4) ◽  
pp. A23-A23
Author(s):  
A. L. Tatler ◽  
A. E. John ◽  
L. Jolly ◽  
A. J. Knox ◽  
L. Pang ◽  
...  

2000 ◽  
Vol 9 (2) ◽  
pp. 93-99 ◽  
Author(s):  
J. Margaret Hughes ◽  
Craig A. Arthur ◽  
Shane Baracho ◽  
Stephen M. Carlin ◽  
Kristen M. Hawker ◽  
...  

Eosinophils are present throughout the airway wall of asthmatics. The nature of the interaction between human airway smooth muscle cells (ASMC) and eosinophils was investigated in this study. We demonstrated, using light microscopy, that freshly isolated eosinophils from healthy donors rapidly attach to ASMCin vitro. Numbers of attached eosinophils were highest at 2 h, falling to 50% of maximum by 20 h. Eosinophil attachment at 2 h was reduced to 72% of control by anti-VCAM-1, and to 74% at 20 h by anti-ICAM-1. Pre-treatment of ASMC for 24 h with TNF-α, 10 nM, significantly increased eosinophil adhesion to 149 and 157% of control after 2 and 20 h. These results provide evidence that eosinophil interactions with ASMC involve VCAM-1 and ICAM-1 and are modulated by TNF-α.


1995 ◽  
Vol 268 (2) ◽  
pp. L201-L206 ◽  
Author(s):  
C. Vannier ◽  
T. L. Croxton ◽  
L. S. Farley ◽  
C. A. Hirshman

Hypoxia dilates airways in vivo and reduces active tension of airway smooth muscle in vitro. To determine whether hypoxia impairs Ca2+ entry through voltage-dependent channels (VDC), we tested the ability of dihydropyridines to modulate hypoxia-induced relaxation of KCl- and carbamyl choline (carbachol)-contracted porcine bronchi. Carbachol- or KCl-contracted bronchial rings were exposed to progressive hypoxia in the presence or absence of 1 microM BAY K 8644 (an L-type-channel agonist). In separate experiments, rings were contracted with carbachol or KCl, treated with nifedipine (a VDC antagonist), and finally exposed to hypoxia. BAY K 8644 prevented hypoxia-induced relaxation in KCl-contracted bronchi. Nifedipine (10(-5) M) totally relaxed KCl- contracted bronchi. Carbachol-contracted bronchi were only partially relaxed by nifedipine but were completely relaxed when the O2 concentration of the gas was reduced from 95 to 0%. These data indicate that hypoxia can reduce airway smooth muscle tone by limiting entry of Ca2+ through a dihydropyridine-sensitive pathway, but that other mechanisms also contribute to hypoxia-induced relaxation of carbachol-contracted bronchi.


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