Small Airway Smooth Muscle Cells (SASMC)

Small Airway Smooth Muscle Cells（SASMC） originate from lung tissues. SASMC can switch between quiescent, migratory, and proliferative phenotypes in response to extracellular matrix proteins, growth factors, and other soluble mediators. They also are capable of secreting cytokines in response to damage or immunologic provocation. These cells wrap around the small airways in a striped circumferential pattern. The ratio of airway smooth muscle thickness relative to the airway diameter increases in normal peripheral airways.