Quantification of collagen and proteoglycan deposition in a murine model of airway remodelling

Reinhardt, Bottoms, Laurent, Mcanulty

Description

Sub-epithelial extracellular matrix deposition is a feature of asthmatic airway remodelling associated with severity of disease, decline in lung function and airway hyperresponsiveness. The composition of, and mechanisms leading to, this increase in subepithelial matrix, and its importance in the pathogenesis of asthma are unclear. This is partly due to limitations of the current models and techniques to assess airway remodelling. Methods In this study we used a modified murine model of ovalbumin sensitisation and challenge to reproduce features of airway remodelling, including a sustained increase in sub-epithelial matrix deposition. In addition, we have established techniques to accurately and specifically measure changes in sub-epithelial matrix deposition, using histochemical and immunohistochemical staining in conjunction with digital image analysis, and applied these to the measurement of collagen and proteoglycans. Results 24 hours after final ovalbumin challenge, changes similar to those associated with acute asthma were observed, including inflammatory cell infiltration, epithelial cell shedding and goblet cell hyperplasia. Effects were restricted to the bronchial and peribronchial regions with parenchymal lung of ovalbumin sensitised and challenged mice appearing histologically normal. By 12 days, the acute inflammatory changes had largely resolved and increased sub-epithelial staining for collagen and proteoglycans was observed. Quantitative digital image analysis confirmed the increased deposition of sub-epithelial collagen (33%, p < 0.01) and proteoglycans (32%, p < 0.05), including decorin (66%, p < 0.01). In addition, the increase in sub-epithelial collagen deposition was maintained for at least 28 days (48%, p < 0.001). Conclusion This animal model reproduces many of the features of airway remodelling found in asthma and allows accurate and reproducible measurement of sub-epithelial extra-cellular matrix deposition. As far as we are aware, this is the first demonstration of increased sub-epithelial proteoglycan deposition in an animal model of airway remodelling. This model will be useful for measurement of other matrix components, as well as for assessment of the molecular mechanisms contributing to, and agents to modulate airway remodelling.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2005
• Nombre de lectures: 0
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Pga e 1fo1  ( 3 apegum nr bet nor foaticnoitrup esops)

Abstract Background: Sub-epithelial extracellular matrix depo sition is a feature of asthmatic airway remodelling associated with severity of disease, decline in lung function and airway hyperresponsiveness. The composition of, and mechanisms leading to, this increase in subepithelial matrix, and its importance in the pathogenesis of asthma are unclear. This is partly due to limitations of the current models and te chniques to assess airway remodelling. Methods: In this study we used a modified murine mo del of ovalbumin sensitisation and challenge to reproduce features of airway remodelling, including a sustained increase in sub-epithelial matrix deposition. In addition, we have established techniques to accu rately and specifically measure changes in sub-epithelial matrix deposition, us ing histochemical and immunohistochemical staining in conjunction with digital imag e analysis, and applied these to the measurement of collagen and proteoglycans. Results: 24 hours after final ovalbumin challenge, chan ges similar to those associated with acute asthma were observed, including inflammatory cell infiltration, epithelial cell shedding and goblet cell hyperplasia. Effects were restricted to the bronchial and peribronchial regions with parenchymal lung of ovalbumin sensitised and chal lenged mice appearing histologically normal. By 12 days, the acute inflammatory changes had largel y resolved and increased sub-epithelial staining for collagen and proteoglycans was observed. Quan titative digital image analysis confirmed the increased deposition of sub-epit helial collagen (33%, p < 0.01) and proteoglycans (32%, p < 0.05), including decorin (66%, p < 0.01). In addition, the in crease in sub-epithelial collagen deposition was maintained for at least 28 days (48%, p < 0.001). Conclusion: This animal model reproduces many of th e features of airway remodelling found in asthma and allows accura te and reproducible measurement of sub-epithelial extra-cellular matrix deposition. As far as we are aware, this is th e first demonstration of increased sub-epithelial proteoglycan deposition in an animal model of ai rway remodelling. This model will be useful for measurement of other matrix components, as well as for assessment of the molecular mechanisms contributing to, and agents to modulate airway remodelling.

Published: 08 April 2005 Received: 27 September 2004 Respiratory Research 2005, 6 :30 doi:10.1186/1465-9921-6-30  Accepted: 08 April 2005 This article is available from: http:/ /respiratory-research.com/content/6/1/30 © 2005 Reinhardt et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the orig inal work is properly cited.

Respiratory Research

Address: Centre for Respiratory Research, University College London, Rayne Building, 5 University Street, London WC1E 6JJ, UK Email: Alistair K Reinhardt - [e-mail] t; Stephen E Bottoms - s.botto [e-mail]; Geoffrey J Laurent - [e-mail]; Robin J McAnulty* - [e-mail] * Corresponding author

Research Open Access Quantification of collagen and pr oteoglycan deposition in a murine model of airway remodelling Alistair K Reinhardt, Stephen E Bottoms, Geoffrey J Laurent and Robin J McAnulty*

Bio Med  Central