Extracellular Matrix Regulates Enhanced Eotaxin Expression in Asthmatic Airway Smooth Muscle Cells

Rationale: Altered airway smooth muscle (ASM) function and enrichment of the extracellular matrix (ECM) with fibronectin and collagen are key features of asthma. Previously, we have reported these ECM proteins enhance ASM synthetic function.Objective: We compared ASM cultured from endobronchial biopsies from subjects with and without asthma to assess if asthmatic cells were hypersecretory and determined whether the underlying mechanism involved autocrine ECM production.Methods and Measurements: Cells from subjects with and without asthma were cultured on plastic or in plates precoated with ECM proteins. Cytokine production was evaluated by enzyme-linked immunosorbent assay and by reverse transcriptase–polymerase chain reaction. Function-blocking integrin antibodies were used to identify integrin involvement.Results: Baseline eotaxin and its production after stimulation with interleukin (IL)-13, IL-1β, or tumor necrosis factor-α was increased (2.5- to 6.0-fold) in ASM cells cultured from subjects with asth...