Eosinophil-induced airway smooth muscle cells remodeling is attenuated by blocking of RGD-binding integrins in asthma

Abstract

Objective: Adherence of eosinophils to airway smooth muscle cells (ASMC) via integrin-ligand interaction may cause ASMC proliferation and extracellular matrix (ECM) proteins overproduction leading to ASM remodeling in asthma. Aim: To investigate the role of integrins in eosinophil effects on ASMC remodeling in asthma. Material and methods: Individual combined cell cultures of immortalized human ASMC and eosinophils from peripheral blood of 18 asthmatic and 10 healthy individuals were prepared. Eosinophils adhesion was evaluated by eosinophil peroxidase activity assay; genes expression levels of TGF- β 1 , WNT-5a, fibronectin and collagen in ASMC - by RT-PCR analysis; ASMC proliferation - by Alamar Blue method; integrins on eosinophils were blocked by Arg-Gly-Asp-Ser (RGDS) peptide. Results: Asthmatic eosinophils demonstrated higher adhesion to the ASMC significantly enhancing TGF-β 1 , WNT-5a, fibronectin, collagen genes expression in ASMC and ASMC proliferation compared to effect of eosinophils derived from healthy subjects. RGDS peptide significantly reduced adhesion of asthmatic eosinophils to ASMC by 21,2% whereas adhesion of healthy eosinophils was decreased only by 10,7%. Blocking of integrins of asthmatic eosinophils significantly reduced TGF-β 1 , WNT-5a and ECM gene expression in ASMC and ASMC proliferation (by 11,5%). However incubation of healthy eosinophils with RGDS peptide had no suppressing effect on gene expression in ASMC and ASMC proliferation. Conclusion: Blocking of RGD-binding integrins reduces eosinophil-induced ASMC remodeling in asthma.