In vitro study of interleukin-5 (IL-5) in human eosinophilic chronic rhinosinusitis cell culture

Background: Eosinophilic chronic rhinosinusitis (ECRS) is an in inflammatory disease in which the epithelial mesenchymal unit appears to be important in regulating the pathological mechanisms. Changes in adhesion molecule (AM) expression by inflammatory cells have been reported. The damage of respiratory epithelium in allergic diseases has a close correlation with the extent of eosinophil infiltration. In our study, we we investigated the effect of IL-5 on beta-catenin and E-cadherin levels in ECRS. Materials and Methods: ECRS cell cultures were incubated with IL-5 and beta-catenin / E-cadherin levels were analysed after 8-72 hours using cytokine immunoassay and immunohistochemistry. Results: Eight hours of incubation with IL-5 resulted in 0.19 ng/ml E-cadherin (15.27 ng/ml beta-catenin), whereas in the control 0.14 ng/ml (15.45 ng/ml beta-catenin) was detectable. After 24 and 48 hours, 0.18 ng/ml (16.47 ng/ml beta-catenin) and 0.33 ng/ml (17.88 ng/ml beta-catenin) were measured in the incubated cell cultures, respectively; 72 hours of incubation with IL-5 resulted in 0.14 ng/ml (19.36 ng/ml beta-catenin), whereas 0.17 ng/ml (20.09 ng/ml P-catenin) was determined in the controls. This study demonstrated a significant decrease in E-cadherin expression in cell cultures after stimulation with IL-5, especially in incubation-time adjusted analysis. However, the immunostaining was restricted to the membrane of the cells. Conclusion: In regard to the increased mural expression of AM, we believe that a fibrotic reaction similar to that in chronic obstructive pulmonary disease takes place in patients suffering from ECRS.