Abstracts

#39 Changes in Lung Tissue Proteome in an Allergen Challenge Mouse Model of Asthma


Thomas H Mahood, CHRIM / University of Manitoba; Chris Pascoe, CHRIM / University of Manitoba; Aruni Jha, CHRIM / University of Manitoba; Peyman Ezzati, Manitoba Centre for Proteomics and Systems Biology / University of Manitoba; Sujata Basu, CHRIM / University of Manitoba; Victor Spicer, Manitoba Centre for Proteomics and Systems Biology / University of Manitoba; Neeloffer Mookherjee, Manitoba Centre for Proteomics and Systems Biology / University of Manitoba; Andrew Halayko, CHRIM / University of Manitoba


Introduction

A leading animal model for asthma uses repeated intranasal (i.n.) challenge with house dust mite (HDM) in adult mice, which promotes airway remodelling and hyperresponsiveness. Comprehensive analysis of the changes in the lung proteome with HDM challenge is sparse. The objective of this study was to use a proteomics approach to characterize and quantify global protein changes in the lung following HDM challenge.


Methods

Female, BALB/c mice (6-8 weeks, n=4) were subjected to HDM i.n. challenge (25µg/mouse) 5 times per week for two weeks. Lung function and airway responsiveness to methacholine was measured using a small animal ventilator. Immune cell counts and differentials in lung lavage were performed. Age-matched allergen-naïve and HDM challenged lung tissue specimens were snap frozen until processed. For each sample, protein homogenates were concentrated by filter centrifugation, trypsinized, and subjected to HPLC-MS/MS. Proteins were identified and quantified using X!Tandem. Statistical and pathway analysis was conducted using Multiple Experiment Viewer and Ingenuity Pathway Analysis (IPA).


Results

HDM challenge induced significant increases in maximum airway resistance, tissue dampening and tissue elastance in response to 50mg/mL methacholine (p<0.0001; two-way ANOVA). We observed a 148% increase in BALF total inflammatory cell number compared to allergen-naïve (p<0.05, ANOVA). We identified 286 up- and 72 down-regulated proteins that were significantly regulated by allergen challenge. Top differentially regulated pathways included antigen presentation, oxidative stress and mitochondrial dysfunction. IPA also identified that lipid conversion and metabolism pathways are activated upon allergen challenge.


Conclusion

Using system’s biology we have defined changes in the lung tissue proteome upon HDM challenge that alters lung function and produces a rich inflammation that mimics severe asthma. We describe an inflammatory tissue profile with altered lipid conversion and metabolism. Our platform provides an approach to decipher pathobiological mechanisms and response to new therapies in chronic lung diseases such as asthma.