The basement membrane and its role in pulmonary disease

The basement membrane is a highly specialized type of extracellular matrix. Its core structure is conserved in all tissues, but protein isoforms and various associated proteins make it unique to every tissue. The basement membrane underlies epithelial and endothelial cells and plays a crucial role as a tissue barrier and growth factor reservoir; it mediates cell signaling and performs filtration. Due to its key role in upholding tissue function, changes to its composition can drive disease. In the lungs, the basement membrane performs the specialized role of gas transfer, and alterations to its composition may be fatal. In pulmonary fibrosis, injury to the basement membrane may mediate a profibrotic response from fibroblasts and drive disease development and progression. A key feature of asthma is thickening of the basement membrane area, while chronic obstructive pulmonary disease is associated with a fragmented basement membrane.