Abstract
Steroid-insensitive asthma-related airway inflammation is associated with the expression of epidermal growth factor receptor (EGFR) tyrosine kinase in asthmatic bronchial epithelium. Proinflammatory cytokines IL-6 and IL-8 are related to steroid-insensitive asthma. It is currently unknown how EGFR-tyrosine kinase inhibitors (EGFR-TKIs) affects house dust mite (HDM)-induced asthma in terms of inflammatory cytokines related to steroid-resistant asthma and further signaling pathway. Cytokine expressions and EGFR signaling pathway were performed by ELISA, reverse transcriptase PCR, real-time PCR, and Western blot in cell-line models. AMP-activated protein kinase (AMPK) pathway-related inhibitors were applied to confirm the association between EGFR-TKI and AMPK pathway. HDM induced IL-6 and IL-8 in a dose-dependent manner. Both Erlotinib (Tarceva) and Osimertinib (AZD-9291) reduced the levels of HDM-stimulated IL-6 and IL-8 levels in BEAS-2B cells. AZD-9291 was more effective than Erlotinib in inhibiting phospho-EGFR, and downstream phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and phopho-signal transducer and activator of transcription 3 (p-STAT3) pathway signaling. In addition, AMPK pathway-related inhibitor, Calcium-/calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor, down-regulated IL-8, but EGFR-TKI had no effect on AMPK pathway. Our findings highlight EGFR-TKIs, Tarceva, and AZD-9291, attenuate HDM-induced inflammatory IL-6 and IL-8 cytokines via EGFR signaling axis pathway, but not AMPK signaling pathway.