The Effects and Mechanisms of the YY1/EGFR Axis on Inflammation and Oxidative Stress in Asthma.

Abstract

To investigate the expression of the transcription factor Yin and Yang 1 (YY1) and the effect of oxidative stress on the upregulation of epidermal growth factor receptor (EGFR) expression in a bronchial epithelial cell line. A bronchial epithelial cell line (BEAS-2B) was stimulated with interleukins (IL-4, IL-13, and IL-17A) to simulate the asthma microenvironment. Total RNA and total protein were extracted from the BEAS-2B cells, and the expression of inflammatory markers (TSLP and IL-25) and YY1/EGFR was determined. EGFR was overexpressed/inhibited in BEAS-2B cells, and changes in cell activity (CCK-8), thioredoxin reductase (TrxR), and malonaldehyde (MDA) expression were identified. EGFR expression was determined after interference with YY1. The binding sites of the YY1 and EGFR promoter regions were predicted by online databases. Precipitation of YY1 in the EGFR promoter region was investigated via a chromatin immunoprecipitation (ChIP) assay. After IL-4, IL-13 and IL-17A were used to stimulate BEAS-2B cells, the expression levels of inflammatory markers (TSLP and IL-25) and EGFR were significantly increased in the asthma cell model. After EGFR was overexpressed, EGFR mRNA and protein expression levels were significantly increased, cell viability was significantly increased, the relative expression level of MDA was significantly increased, and the relative expression level of TrxR was significantly decreased. After the expression of EGFR was disrupted, the EGFR mRNA and protein expression levels were significantly decreased, the cell viability was significantly decreased, the relative expression level of MDA was significantly decreased, and the relative expression level of TrxR was significantly increased. After the expression of YY1 was disrupted, the EGFR mRNA and protein expression levels were significantly decreased, and the results of the ChIP assay suggested that YY1 bound to the EGFR promoter region. The YY1/EGFR axis promotes inflammation and increases oxidative stress in BEAS-2B cells.