Effects of amentoflavone on airway inflammation in asthmatic young rats by regulating cGAS-STING signal pathway

XIONG Tiantian; WANG Rui; XIE Xiong; ZOU Yulin

doi:10.13431/j.cnki.immunol.j.20240020

Abstract：The aim of this study was to investigate the effect of amentoflavone(AF)on airway inflammation in asthmatic young rats and its mechanism.The asthmatic model of young SD rats was established by intraperitoneal injection combined with nebulization of ovalbumin(OVA).The rats were randomly grouped into asthma model(M)group,dexamethasone(DXMS)group,AF low(AF L),AF medium(AF M),AF high(AF H)dose group and normal control group(CT)group.After administration,the airway reactivity was detected with non-invasive lung function instrument and the inflammatory cell types in bronchoalveolar lavage fluid(BALF)were analyzed and counted by Giemsa staining.Furthermore,hematoxylin-eosin(HE)staining was applied to evaluate the pathological morphology of lung and bronchial tissues,enzyme-linked immunosorbent assay(ELISA)kits were used to detect the content of inflammatory factors in serum,Western blot was applied to detect the protein expression of GMP-AMP synthase(cGAS),interferon gene stimulator(STING),phosphorylated interferon regulatory factor 3(p-IRF3)and interferon regulatory factor 3(IRF3)in lung tissue of rats.Compared with the CT group,the asthma model group showed obvious pathological damage of bronchial tissue and lung tissue,higher level of airway reactivity,higher pathological scores of lung tissue and bronchial tissue,increased total number of inflammatory cells and the number of monocytes,eosinophils,neutrophils and lymphocytes in BALF,higher levels of inflammatory factors in serum,and higher expression levels of cGAS,STING and p-IRF3/IRF3 proteins in lung tissue(P<0.05).Compared with the M group,the pathological damage of lung and bronchus tissue in asthmatic rats was relieved after treatment with DXMS and high-dose AF,the airway reactivity,pathological score of lung tissue and bronchial tissue,total number and classification of inflammatory cells in BALF,inflammatory factors in serum and expression of cGAS,STING,p-IRF3/IRF3 proteins in lung tissue were obviously lower(P<0.05).In conclusion,AF can alleviate airway inflammation in asthmatic young rats,possibly by inhibiting cGAS-STING signal pathway.