Mouse serum exosomal proteomic signature in response to asbestos exposure.

Asbestos-induced diseases like fibrosis and mesothelioma are very aggressive, without any treatment options. These diseases are diagnosed only at the terminal stages due to lack of early stage biomarkers. The recent discovery of exosomes as circulating biomarkers led us to look for exosomal biomarkers of asbestos exposure in mouse blood. In our model, mice were exposed to asbestos as a single bolus dose by oropharyngeal aspiration. Fifty-six days later blood was collected, exosomes were isolated from plasma and characterized and subjected to proteomic analysis using Tandem Mass Tag labeling. We identified many proteins, some of which were more abundant in asbestos exposed mouse serum exosomes, and three selected proteins were validated by immunoblotting. Our study is the first to show that serum exosomal proteomic signatures can reveal some important proteins relevant to asbestos exposure that have the potential to be validated as candidate biomarkers. We hope to extrapolate the positive findings of this study to humans in future studies.