A proteomics approach to the study of bleomycin- induced lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most severe lung fibrotic form and very few pharmacological therapies are available at present. Key events in the onset of the disease are the activation of fibroblasts to myofibroblasts and the production and release of extracellular matrix (ECM) and molecular factors. Primary murine lung fibroblasts were isolated and their activation induced by Bleomycin (BLM) treatment. Extracellular Vesicles (EV) were isolated and protein extracted. Released soluble proteins (Secretome) and EV-derived proteins were reduced, alkylated and trypsin digested. A nano-LC-MS/MS SWATHTM approach was used for the proteomics analyses. Specific proteins with a putative role in the transition from physiological to fibrotic conditions, such as several matrix metalloproteinases (MMPs), osteopontin (OPN), chitinase-3-like protein1 (CHI3L1) and CD44 resulted differentially released from BLM-treated fibroblasts as compared with untreated lung fibroblasts. Our results provide further understanding of the pathophysiological features of lung fibrosis, and suggest specific target for pharmacological treatments.