Airway vascular remodeling in asthma.

Several characteristic changes occur in the bronchial wall in asthma, including specific changes to the vasculature. These result in an increase in vessel numbers per unit area, as well as increased vessel activity suggested by vasodilatation, vessel leakage, and cellular margination with transmigration to target tissues. This combined action in asthma leads to airway-wall thickening and reduced airflow. Each component of the vascular response has been shown to be controlled by a range of inflammatory mediators and growth factors. These factors are themselves regulated by a complex process initially involving gene expression, transcription, and translation at the molecular level, then subsequent protein release, binding to matrix elements, endothelial cell activation, and a proliferative endothelial response. Many commonly used airway medications are capable of modulating the vascular response to inflammatory stimuli. New therapies might improve airflow through better regulation of vessel growth, dilatation, and leakage in the airway wall.