Hyaluronan Directs Alveolar Type II Cell Response to Acute Ozone Exposure in Mice.

Becoming more frequent due to climate change, ozone (O) exposures can cause lung injury. Alveolar type 2 (AT2) cells and hyaluronan (HA), a matrix component, are critical to repairing lung injury and restoring homeostasis. Here, we define the impact of HA on AT2 cells following acute O exposure.

Interleukin-13 disrupts type 2 pneumocyte stem cell activity.

The T helper 2 (Th2) inflammatory cytokine interleukin-13 (IL-13) has been associated with both obstructive and fibrotic lung diseases; however, its specific effect on the epithelial stem cells in the gas exchange compartment of the lung (alveolar space) has not been explored. Here, we used in vivo lung models of homeostasis and repair, ex vivo organoid platforms, and potentially novel quantitative proteomic techniques to show that IL-13 disrupts the self-renewal and differentiation of both murine and human type 2 alveolar epithelial cells (AEC2s). Significantly, we find that IL-13 promotes ectopic expression of markers typically associated with bronchiolar airway cells and commonly seen in the alveolar region of lung tissue from patients with idiopathic pulmonary fibrosis.