Abstract
OBJECTIVES: To study the expression of the transcription factor GATA1 in bronchial asthma (referred to as asthma) and its effect on the expression level of the asthma susceptibility gene orosomucoid 1-like protein 3 (ORMDL3), along with the underlying molecular mechanisms. METHODS: The study included 28 cases of moderate asthma, 46 cases of severe asthma, and 12 normal controls from the Gene Expression Omnibus (GEO) database. The mRNA expression levels of GATA1 and ORMDL3 were analyzed among the asthma patients and the normal controls, including their correlation. The pGL-185/58 plasmid was co-transfected with GATA1 gene siRNA (si-GATA1 group) and siRNA negative control (si-control group) into BEAS-2B cells. Bioinformatics methods were used to predict GATA1 binding sites in the promoter region of the ORMDL3 gene. The dual-luciferase reporter gene system was employed to assess the promoter activity of ORMDL3, while real-time quantitative PCR and Western blotting were used to measure the mRNA and protein expression levels of GATA1 and ORMDL3. Chromatin immunoprecipitation (ChIP) assays were conducted to determine whether GATA1 binds to the promoter region of ORMDL3. RESULTS: The expression levels of GATA1 and ORMDL3 mRNA were significantly higher in the severe asthma group compared to the normal control group (P<0.001). Positive correlations were observed between GATA1 mRNA and ORMDL3 mRNA expression levels in both the moderate and severe asthma groups (r=0.636 and 0.341, respectively; P<0.05). In BEAS-2B cells, the dual-luciferase reporter assay revealed that ORMDL3 promoter luciferase activity, as well as ORMDL3 mRNA and protein expression levels, were lower in the si-GATA1 group compared to the si-control group (P<0.05). ChIP assay results demonstrated that GATA1 could bind to the promoter region of ORMDL3. CONCLUSIONS: The expression of GATA1 is increased in asthma patients, which may regulate the promoter activity and expression of the asthma susceptibility gene ORMDL3.