Measurement and impact of remodeling in the lung: airway neovascularization in asthma

Expansion of the airway wall vascular compartment has recently been established as a feature of asthma involving both enlargement of existing vascular structures and the formation of new vessels (angiogenesis). Both processes are likely to occur together and are fundamental for supporting the many aspects of tissue inflammation and remodeling manifest in the clinical symptoms of airway disease. Multiple growth factors are implicated in airway angiogenesis, with vascular endothelial growth factor among the most important. Other asthma-associated stimuli, including ADAM33, environmental tobacco smoke, and rhinovirus infection, are emerging as proangiogenic regulators. Increasing attention is also focused on the complex interplay of airway wall inflammatory and structural cells, including airway smooth muscle in driving expansion of the bronchial submucosal vascular plexus in asthma. Here, we provide a brief update on recent developments in this emerging area and highlight the potential role played by airway smooth muscle.