1. Selenium ameliorates <italic>Staphylococcus aureus</italic>-induced inflammation in bovine mammary epithelial cells by inhibiting activation of TLR2, NF-κB and MAPK signaling pathways.
- Author
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Wang, Heng, Bi, Chongliang, Wang, Yinjie, Sun, Jun, Meng, Xia, and Li, Jianji
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INFLAMMATION , *CATTLE diseases , *EPITHELIAL cells , *BOVINE mastitis , *TOLL-like receptors , *PROTEIN kinases - Abstract
Background:
Staphylococcus aureus (S. aureus ) internalization into bovine mammary epithelial cells (bMECs) is considered an important pathogenic mechanism for the establishment of mastitis. Given the interesting link between selenium (Se) status and mastitis, our objective was to prove that Se was essential to suppress pro-inflammatory mediators, in part, by modulation of Toll-like receptor2 (TLR2), nuclear factor kappaB (NF-κB) and mitogen activated protein kinase (MAPK) signal transduction pathway in bMECs. Results: Results showed that Se (0~ 16 μM) did not affect the growth of bMECs. The mRNA expression of TLR2, Myeloid differentiation factor 88 (Myd88), Interleukin-1 receptor-associated kinase4 (Irak4), Interleukin-1 receptor-associated kinase1 (Irak1) and TNF receptor-associated factor6 (Traf6) in TLR2 signal pathway were increased or significantly increased byS. aureus . Se played an important role in regulating the genes expression of TLR2, Myd88, Traf6 but not in controlling the expression of Irak4 and Irak1. In addition, Se exerted strong inhibitory effects on the genes expression of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) induced byS. aureus . To further investigate the possible signaling mechanisms involved in the processes, we analyzed the role of MAPK and NF-κB signaling pathway in inflammation response inS. aureus -stimulated bMECs in vitro. Results showed that the phosphorylation of inhibitory kappaB alpha (IκBα ),p65 ,p38 and extracellular regulated protein kinase (Erk ) were significantly increased inS. aureus -stimulated bMECs. It indicated thatS. aureus activated NF-κB and MAPK signaling pathway. We also examined the effects of Se on the phosphorylation ofIκBα, p65, p38 andErk in NF-κB and MAPK signaling pathway, which have well been proved to control the synthesis and release of pro-inflammatory mediators during inflammation. The findings are exciting, that pretreatment with Se (4, 8 μM) significantly suppressed the phosphorylation ofIκBα ,p65 ,p38 andErk . Conclusions: These results suggest that Se down-regulates inflammatory mediators TNF-α, IL-1β and IL-6 gene expressions via TLR2, NF-κB and MAPK signaling pathway inS. aureus -stimulated bMECs, which may be responsible for the anti-inflammatory effect of Se. [ABSTRACT FROM AUTHOR]- Published
- 2018
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