Bisphenol A attenuates the therapeutic effect of the selective G protein-coupled estrogen receptor agonist G-1 on allergic rhinitis inflammation in mice

Bisphenol A (BPA) is found in many plastics widely used in everyday life and affects the immune system. Previous studies found that the selective G protein coupled estrogen receptor (GPER) agonist G-1 can reduce the inflammation associated with asthma and allergic rhinitis (AR). BPA also interferes with the protective effect of estradiol against myocardial ischemia-reperfusion injury.We explored whether BPA attenuates the effect of G-1 on inflammation in a mouse AR model.The AR model was established by sensitizing and stimulating female BALB/c mice with ovalbumin (OVA) and G-1/BPA. Eosinophils, neutrophils, and lymphocyte subsets (including T and B cells) in nasal mucosa and Th2 and Treg cells in the spleen were detected by flow cytometry. Cytokines and transcription factors characteristic of Th2 and Treg cells in nasal mucosa were detected using cytometric bead arrays and quantitative PCR, respectively.G-1 reduced OVA-induced nasal mucosal inflammation in mice. The proportions of eosinophils, neutrophils, Siglec-F+ neutrophils, lymphocytes, and T cell subsets were reduced by G-1, and this effect was attenuated by BPA. G-1 significantly decreased the Th2 population and levels of IL-4, IL-5, IL-13 and GATA-3; these effects were attenuated by BPA. The enhanced Treg response (as evidenced by an increased Treg population and higher IL-10 and Foxp3 levels) mediated by G-1 tended to be reduced by BPA.We found that G-1 reduced OVA-induced nasal mucosal inflammation and significantly decreased the Th2 response, while increasing the Treg response. These effects were attenuated by BPA.