Selenium ameliorates S. aureus-induced inflammation through ROS-mediated NLRP3 inflammasome in bovine mammary epithelial cells

Abstract

Background Some research has indicated that selenium (Se) plays a significant role during mastitis. However the intracellular anti-inflammatory effect of Se is not fully clear. Due to the ability of Staphylococcus aureus ( S. aureus ) to internalize into host cell, in this study we explored whether Se could regulate inflammation induced by S. aureus through reactive oxygen species (ROS)-mediated NLRP3 inflammasome in bMECs. Result bMECs were treated with 8 μmol/L Na 2 SeO 3 for 12 h before infected with S. aureus for 2 h. Through flow cytometry, Western blot and qPCR analysis, ROS and NLRP3 imflammasome were detected. Result shown that the production of ROS was increased by S. aureus , Se exerted strong inhibitory effects on the production of ROS; The protein expression of NLRP3 inflammasome including NLRP3, ASC and Caspase-1 increased significantly after S. aureus infection, Se played an important role in regulating the expression of NLRP3, ASC and Caspase-1; To further investigate the anti-inflammatory effect of Se, the expression level of IL-1β associated molecule pro-IL-1β and IL-1β were detected. Result shown that the mRNA expression of IL-1β was up-regulated by S. aureus and after Se treatment the expression level of IL-1β mRNA was markedly down-regulated, meanwhile Se play a regulation effect on the protein expression of Pro-IL-1β and IL-1β. Conclusions Here we show that ROS is involved in bMECs inflammation induced by S. aureus and Se ameliorates S. aureus -induced inflammation through ROS-mediated NLRP3 pathway in bMECs.