Cell Death and Repair in Lung Disease

The lung is a multicellular organ that functions in gas exchange. Both resident (e.g., epitheLial and fibroblast) and immune (e.g., macrophages and lymphocytes) cells are subject to turnover by cell death mechanisms. In the lung, cell death incurred during injury or disease may occur by several mechanisms, including apoptosis, necrosis, pyroptosis, and others. Programmed cell death pathways such as apoptosis play fundamental roles in tissues homeostasis and developmental regulation, and may also play adaptive or pro-pathogenic roles in disease. Necrosis is primarily a detrimental process promoting tissue inflammation. Autophagy, a homeostatic process, may occur in the context of lung disease, and is often associated with cell death pathways. Pathological mechanisms involving cell death have been proposed for several lung diseases, including chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and pulmonary hypertension. Therapeutic strategies aimed at modulating autophagy, apoptosis, and necrosis may have future appLications in inflammatory lung diseases.