Grant: Travel Awards - Institute Community Support

Pulmonary fibrosis (PF) can be caused by an identifiable irritation to the lungs, but in many cases the cause is unknown. In cases when the cause of PF is unknown, the diagnosis is idiopathic pulmonary fibrosis (IPF). IPF, the most common form of the idiopathic interstitial pneumonias and worst prognosis, is a chronic and fatal disease of unknown cause. It is characterized by proliferation of scar-forming cells (fibroblasts), and extensive deposition of scar tissues and extracellular matrix (ECM). The ECM microenvironment is characterized by altered biochemical and biomechanical properties and stores abundant amounts of growth factors, all of which affect the behaviour of lung cells. It is believed that many cell types contribute to lung fibrosis. The number of mast cell is increased in IPF lungs, but very little is known about its role in fibrosis. Our previous work demonstrates that mast cells are increased in the fibrotic lesions in the chronic phase of experimental pulmonary fibrosis in rodents. We hypothesized that ECM microenvironment may affect mast cells' function and characteristics. To address these questions, we used our unique ex vivo bath model and in vitro lung decelluralization technique. Our data indicate that stiffer ECM can induce mast cell degranulation and also change mast cells' phenotypes to a profibrotic phenotype. This study indicates the possibility that the mast cell is a promising target to inhibit the development of pulmonary fibrosis.