The aim of the present study is to examine the potential effect of dexamethasone (DEX) and taurine (TAU) on endoplasmic reticular stress (ERS) and inflammation. The macrophages were pre-treated with DEX or TAU, and the level of ERS and pro-inflammatory response was evaluated in LPS-activated macrophages. The expression of ERS marker proteins (GRP78 and CHOP) and the pro-inflammatory cytokines (IL-1β and IL-6) was analyzed by immunoblotting and ELISA of LPS-induced macrophages. At lower concentrations (<50 nM), DEX alone reduced the levels of ERS and pro-inflammatory markers. Similarly, TAU reduced the expression of LPS-induced ERS and pro-inflammatory markers. When treated with a combination of DEX and TAU, however, the macrophages showed even a greater level of reduction in ERS and pro-inflammatory responses. The RT-qPCR data indicate that the reduction of ERS markers is caused by the inhibition of their own transcriptional expression. The significant level of reduction can be interpreted as a strong synergistic effect (p < 0.01). In summary, the results strongly indicate that a single pre-treatment of DEX or TAU may attenuate ERS and inflammation in LPS-induced macrophages at the concentrations tested in this study. Most importantly, concurrent treatment of macrophages by both agents reduced the level of ERS and pro-inflammatory cytokines in a synergistic fashion.
Keywords: Cytokine; Dexamethasone; ER stress; Inflammation; Macrophage; Taurine.
© 2022. The Author(s), under exclusive license to Springer Nature Switzerland AG.