Synthetic functions of airway smooth muscle in asthma.

Studies now show that the airway smooth muscle cell, in addition to its contractile function, can participate in and coordinate the inflammatory response. In response to inflammatory cytokines, the airway smooth muscle cell produces cytokines, chemokines, growth factors and cell adhesion molecules leading to inflammatory cell chemotaxis, hyperplasia and hypertrophy. Anti-inflammatory mediators are also produced suggesting a dual role in inflammation. Moreover, in response to growth stimuli the cells may adopt a phenotype more suited to 'synthetic' function. These issues are discussed in this article by Simon Johnson and Alan Knox, who also point to ways in which some of these pathways offer future therapeutic potential in asthma.