Selenium and Taurine Combination Is Better Than Alone in Protecting Lipopolysaccharide‐Induced Mammary Inflammatory Lesions via Activating PI3K/Akt/mTOR Signaling Pathway by Scavenging Intracellular ROS

Abstract

Mastitis is mainly induced by gram-negative bacterial infections, causing devastating economic losses to the global cattle industry. Both selenium (Se) and taurine (Tau) exhibit multiple biological effects, including reducing inflammation. However, no studies have reported the protective effect of the combined use of Se and Tau against mastitis, and the underlying mechanisms remain unclear. In this study, lipopolysaccharide (LPS), the vital virulence factor of gram-negative bacteria, was used to construct the in vivo and vitro mastitis models. The results of in vivo model showed that Se and Tau combination was more effective than either substance alone in reducing tissue hyperemia, edema, and neutrophil infiltration in the mammary acinar cavity, improving the blood-milk barrier in LPS-induced mice mastitis, and decreasing the expression of proinflammatory factors and the activity of MPO. Moreover, Se and Tau combination significantly increased the levels of LPS-induced reduction in PI3K/Akt/mTOR, but the expressions of TLRs and NLRP3 were not significantly changed in the mammary tissue. In the in vitro experiments, the effects of Se and Tau combination or alone on inflammatory factors, inflammatory mediators, MPO activity, and blood-milk barrier were consistent with those in vivo. The Se and Tau combination has also been found to increase the survival rate of BMECs compared with each substance alone via promoting cellular proliferation and inhibiting apoptosis. Also, it has been confirmed that this combination could restore the LPS-induced inhibition in the PI3K/Akt/mTOR signaling pathway. Inhibition of mTOR by Rapamycin counteracted the combined protection of SeMet and Tau against LPS-induced inflammatory damage, the inhibition of PI3K by LY294002 blocked the activation of mTOR, and the accumulation of ROS by the ROS agonist blocked the activation of PI3K. In conclusion, these findings suggested that Se and Tau combination was better than either substance alone in protecting LPS-induced mammary inflammatory lesions by upregulating the PI3K/Akt/mTOR signaling pathway.

Huayu Qutan Recipe promotes lipophagy and cholesterol efflux through the mTORC1/TFEB/ABCA1‐SCARB1 signal axis

“…Taurine, a main component in HYQT. Previous studies have found that taurine can regulate autophagy and regulate mTOR protein expression 30 . In this study, the effect of taurine on lipid accumulation in RAW 264.7 cells was detected.…”

“…Previous studies have found that taurine can regulate autophagy and regulate mTOR protein expression. 30 In this study, the effect of taurine on lipid accumulation in RAW 264.7 cells was detected. Furthermore, WB analysis was used to verify the regulation of taurine on lipophagy and mTORC1/TFEB signalling pathway.…”

Elevated FBXL6 expression in hepatocytes activates VRK2-transketolase-ROS-mTOR-mediated immune evasion and liver cancer metastasis in mice

“…This finding further confirms that TKT activity depends on FBXL6. Intercellular ROS scavenging can activate the mTOR pathway 37 , 38 . We found that treatment with the ROS inhibitor VAS2870 significantly increased the protein levels of PD-L1 and p-mTOR (whose downstream targets are p-S6K and p-4EBP1) and attenuated the TKT knockdown-mediated decreases in cell proliferation and migration (Fig.…”

Exosomes in Mastitis—Research Status, Opportunities, and Challenges

“…Selenium is an essential trace element in the body and exhibits various physiological functions, such as anti-inflammatory and antioxidant activities. Many clinical and basic studies have shown that selenium may relieve bovine mastitis by inhibiting the NF-κB and MAPK signaling pathways or activating NRF2 [ 92 , 93 , 94 , 95 , 96 ]. To further explore the molecular mechanism by which selenium alleviates mastitis, Jing et al analyzed the effect of selenium on exosomal RNA derived from MAC-T cells and determined the mRNA levels in exosomes derived from selenium-pretreated normal cells and from cells that had been infected with S. aureus [ 97 ].…”