The protective effect of selenium on the acute injury in S. aureus-infected mouse mammary gland

In this study the protective effect of dietary Selenium during pregnancy on the acute mammary injury induced by S. aureus were observed. Eighty BALB/c pregnant mice were randomly divided into four groups: Control group (CG; Se-deficient basal diet during pregnancy without S. aureus infection; n = 20), Negative control (NG; 0.2 mg/kg Se-supplemented diet during pregnancy without S. aureus infection; n = 20), Positive group (PG; Se-deficient basal diet during pregnancy and infected with S. aureus four days after pregnancy; n = 20) and Treatment group (TG; 0.2 mg/kg Se-supplemented diet during pregnancy and infected with S. aureus. four days after pregnancy; n = 20). 24 h after infection, all mice were euthanized and the mammary tissues were sampling. Pathological section and scanning electron microscope were used to observe the pathologic injury in mammary gland, 54146 genes were detected by high throughput sequencing to identify the differentially expressed gene, ELISA was used to determine the expression level of IL-1β and TNF-α. Results shown that the mammary tissue structure were damaged by S. aureus , after selenium treatment the acute injury lightened, meanwhile 24434 were detected differentially expressed after S. aureus infection, which mainly regulate T cell activation, keratinization, cytokine production. Whereas only 20467 differentially expressed genes were detected in TG, in which genes code T cell activation and cytokine production were marked downregulated and gene code cell adhesion was upregulated. furthermore, selenium treatment significantly decreased the expression level of IL-1β and TNF-α induced by S. aureus . In conclusion, selenium played a protective effect on the acute injury in S. aureus- infected mouse mammary gland.