Harvard Catalyst Profiles

Cigarette smoke is the main cause of emphysema in United States. The community of cells lining our airways plays a collaborative role in the preservation of immune homeostasis in the lung and provides protection from cigarette smoke and the other pollutants in the air we breathe. We have found using histological analyses of precision cut lung slices (PCLSs) that pulmonary neuroendocrine cells (PNECs) have extensions that reach far beyond the individual cell, extending into the basement membrane. Also, in primary airway epithelial cells differentiated on Transwell membranes, we found that PNECs have extensions, suggesting that PNECs differentiate from basal cells and the extensions protrude to cover up to 15-20 neighboring cells. The role of the student will be to conduct immunostaining and examine the contact sites of PNECs with neighboring using confocal microscopy in thin sections (5 µm thick) and PCLSs (200 µm thick). The effect of a protein that modifies the number and histology of PNECs on these contact sites will be evaluated. These studies will have implications how we can treat chronic diseases of the lung in cigarette smokers. The other project is focused on lung inflammation and pulmonary fibrosis. Despite recent advances in the therapeutics available for idiopathic pulmonary fibrosis (IPF), there remains a significant gap in the availability of treatments that can effectively prevent or reverse lung fibrosis. Based on previous studies, we found that a protein called Noxa prevents IPF in mice by inhibiting inflammation and protein oxidation. The student will quantify the extent of oxidized proteins in the lungs of transgenic mice seven days post-bleomycin administration (3 U/kg) using protein analysis. To further investigate how Noxa protects against bleomycin-induced lung fibrosis, the student will use mouse fibroblast cells from Noxa+/+ and Noxa-/- mice to compare glutathionylated proteins after a 12-hour exposure to bleomycin (10 mU/ml). Because we have shown that Noxa affects degradation of oxidized protein by modifying the proteasome, the student will measure immunoproteasomal activity in cell lysates from Noxa-/- fibroblasts treated with a Noxa-derived peptide, followed by bleomycin treatment.