Apoptosis in lung fibrosis and repair.

Cell death by apoptosis has fundamental significance in both normal lung homeostasis and a variety of pathologic processes, and for this reason apoptosis in the lung is a rapidly growing area of investigation. Evidence from human lung biopsy specimens and from animal models of lung fibrosis points to important roles for apoptosis in both the pathogenesis and resolution of fibrotic lesions. As more evidence accumulates, the more apparent becomes the paucity of information on the regulation of this mode of cell death in the many different cell types of the lung parenchyma. This discussion will review the current state of knowledge regarding the roles of apoptosis in lung fibrosis and will focus on its role in pathogenesis.