| Abstract [eng] |
Asthma is a chronic inflammatory airway disease in which eosinophils play an important role in asthma pathogenesis. Eosinophils are not a homogeneous cell population, therefore, their subtypes may perform different functions in the pathogenesis of asthma. Resident eosinophils are associated with the maintenance of tissue homeostasis, whereas inflammatory eosinophils are linked to the inflammatory response, tissue damage and disease progression. One of the possible mechanisms of eosinophil activity is the formation of extracellular traps. However, differences in this process between eosinophil subtypes in asthma have not been investigated. The aim of this study was to investigate differences in eosinophil extracellular trap formation between eosinophil subtypes in asthma. The study included 10 patients with asthma and 6 healthy subjects. Eosinophils were isolated from peripheral blood, their subtypes were separated, the release of mitochondrial- and nuclear-derived extracellular DNA was evaluated, and the expression of genes associated with eosinophil extracellular trap formation, including PADI4, SYK, CYBB, RAC2 and TLR4, was assessed. It was found that resident eosinophils from asthma patients released a higher amount of mitochondrial-derived extracellular DNA than inflammatory eosinophils, while stimulation with granulocyte-macrophage colony-stimulating factor enhanced this process. Differences in nuclearderived extracellular trap formation between the studied groups were not statistically significant. Analysis of gene expression in patients with asthma revealed higher CYBB expression in inflammatory eosinophils, higher PADI4 expression in resident eosinophils and lower SYK expression in inflammatory eosinophils. TLR4 and RAC2 expression did not differ significantly between eosinophil subtypes. When patients with asthma were compared with healthy subjects, increased CYBB and PADI4 expression was observed in resident eosinophils, whereas decreased SYK and TLR4 expression was detected in inflammatory eosinophils. The results of this study indicate that eosinophil subtypes may differ in extracellular DNA release and in the expression of genes associated with eosinophil extracellular trap formation. These differences are important for a better understanding of the role of eosinophils in asthma pathogenesis and may contribute to the search for new disease biomarkers and molecular targets. |
