BelTox Annual Meeting location:Brussels, Belgium date:28 November 2008
Introduction: Up to 15% of all asthma cases in adults are due to chemical exposures at the workplace. The identification of biomarkers of sensitization could help to move diagnosis to an earlier stage. Using a mouse model of chemical-induced asthma we will explore the process of sensitization towards chemicals at the protein and peptide level.
Methods: On days 1 and 8, mice are treated on both ears with toluene diisocyanate (TDI, 0.3% or 3%, 20µl), a known respiratory sensitizer, or a mixture of acetone – olive oil (AOO, vehicle-control). On day 15, lymph nodes are collected and homogenized.
We used two-dimensional differential gel electrophoresis (2D-DIGE) to analyze the differential expression of proteins in TDI and vehicle-treated lymph nodes.
Results: Body weight of control mice and TDI-treated mice did not differ. Interestingly, the weight of auricular lymph nodes significantly increased with an increasing concentration of TDI. 2D-DIGE analysis of these lymph nodes showed 35, 36 and 12 differential proteins comparing 0.3% and AOO, 3% TDI and AOO and 0.3% TDI and 3% TDI respectively. 17 proteins are already identified, among which several structural proteins and lymphocyte specific protein-1.
Conclusion: This study demonstrates the use of 2D-DIGE in the search for (early) biomarkers of chemical-induced asthma. Further studies will have to point out whether (some of) these proteins could act as valuable biomarkers. Therefore, more samples (bronchoalveolar lavage fluid, serum,…) will be analysed.