Selenium Plays an Anti-Inflammatory Role by Regulation NLRP3 Inflammasome in Staphylococcus aureus-Infected Mouse Mammary Gland.

Selenium is an essential micronutrient that plays an important role in immunity. However, the mechanism that Selenium modulates mastitis is not fully clear. In this experiment, we investigated whether selenium can inhibit the activation of the NLRP3 inflammasome in a mouse model of Staphylococcus aureus-induced mastitis. Eighty BALB/c female mice were fed with experimental Selenium deficiency basal diet for 2 weeks to achieve the purpose of selenium consumption until pregnancy. Pregnant mice were randomly divided into four groups (control group; selenium supplement group; Staphylococcus aureus infection group and Staphylococcus aureus infection after selenium supplement group). Twenty-four hours after challenging, all mice were euthanized and mammary tissue samples were aseptically collected. Through pathological staining, western blot analysis, real-time fluorescence quantitative polymerase chain reaction analysis, and enzyme-linked immunosorbent assay, the regulation effect of Selenium on NLRP3 inflammasome was detected. The result showed that compared with the control group, selenium significantly inhibited the expression of NLRP3, ASC, Caspase-1, Caspase-1 p20, and Pro-IL-1β (p < 0.01). Meanwhile the mRNA expression and release of IL-1β was suppressed in the treatment group compared with Staphylococcus aureus infection group (p < 0.01). Therefore, these results suggest that dietary selenium can attenuate Staphylococcus aureus mastitis by inhibition of the NLRP3 inflammasome.