β-Conglycinin is one of the key thermostable anti-nutritional factors in soybean, which has strong immunogenicity that usually leads to weaning in some young animals such as piglets and calves and allergic reaction in rats. Neutrophils are involved in the pathogenesis of an allergy. However, the contribution of functional neutrophils to allergy needs to be clarified. The formation of neutrophil extracellular traps is a novel effector mechanism of neutrophils and has been extensively investigated in recent years. To the best of our knowledge, there is no information available on β-conglycinin-induced NETs. In this study, β-conglycinin-induced NET formation in mice was examined via immunofluorescence analysis and fluorescence microplate reader. The mechanism of β-conglycinin-induced NETs was investigated using inhibitors and fluorescent microplate methods. The results showed that β-conglycinin induced the classical characteristics of NETs, which mainly consist of DNA as the backbone and decorated with histones, myeloperoxidase (MPO) and neutrophil elastase (NE). Moreover, β-conglycinin significantly induced the formation of NETs in a dose-dependent way. NET degrading enzyme DNase I markedly reduced β-conglycinin-induced NETs, which suggests that β-conglycinin indeed triggered the release of NETs. Further investigation showed that the quantitation of NETs was markedly decreased by the inhibitors of reactive oxygen species (ROS)-derived-NADPH oxidase, ERK1/2, p38, Rac and PAD4 signaling pathways, indicating the crucial role of these signaling pathways in β-conglycinin-induced NETs. Furthermore, our findings revealed that β-conglycinin induced the formation of NETs, which is dependent on NADPH oxidase-derived ROS, ERK1/2, p38, Rac and PAD4 signaling pathways. This study is the first to demonstrate the underlying mechanisms of β-conglycinin-induced NET formation, and it could be helpful to understand diarrhea caused by β-conglycinin overexposure in young animals and provides the corresponding theoretical basis for clinical applications.
1 July 2021 in Toxicology and Applied Pharmacology
This study aimed to investigate the protective effects and mechanisms of myricetin on acute liver failure in mice induced by lipopolysaccharide (LPS)/D-galactosamine (D-Gal). Our results showed myricetin (25, 50 and 100 mg/kg) pretreatment significantly improved the pathological changes of liver tissues, decreased serum ALT and AST (p < 0.001) induced by LPS/D-GalN. Moreover, MDA and MPO levels were reduced (p < 0.001), CAT and SOD activities were increased (p < 0.001) with myricetin (50 and 100 mg/kg) pretreatment. Likewise, inflammatory cytokines TNF-α and IL-6 mRNA in liver tissues were markedly decreased (p < 0.001) by myricetin. Besides, Nrf2 protein expression was drastically elevated (p < 0.001) by myricetin (25, 50 and 100 mg/kg). All these findings imply that myricetin may protect against acute liver failure by suppressing inflammation and regulating oxidative stress via Nrf2 signaling, and that it may be a possible strategy to avoid liver damage. Graphical Abstract