Role of autophagy in dexmedetomidine-induced reduction of lipopolysaccharide-caused inflammatory responses in macrophages of mice / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of autophagy in dexmedetomidine-induced reduction of lipopolysaccharide ( LPS)-caused inflammatory responses in macrophages of mice. Methods Mouse mac-rophage cell line RAW264. 7 cultured in vitro were seeded in 6-well or 96-well plates and divided into 4 groups ( n=20 each ) when cell confluence reached 60％ using a random number table method: control group (group Con), LPS group, LPS plus dexmedetomidine group (group LPS+DEX), and LPS plus dexmedetomidine plus autophagy inhibitor 3-MA group (group LPS+DEX+3-MA). PBS was added and cells were cultured for 12 h in group Con. LPS at the final concentration of 1000 ng∕ml was added and cells were incubated for 12 h in group LPS. LPS at the final concentration of 1000 ng∕ml was added, and then dexmedetomidine at the final concentration of 1 μmol∕L was immediately added, and cells were incubated for 12 h in group LPS+Dex. In group LPS+Dex+3-MA, 3-MA at the final concentration of 2 mmol∕L was added and cells were incubated for 1 h, LPS at the final concentration of 1000 ng∕ml was added, and then dexmedetomidine at the final concentration of 1 μmol∕L was immediately added, and cells were incubated for 12 h. Cell viability was detected by CCK-8 assay, and the concentrations of nitrous oxide ( NO) , tumor necrosis factor-alpha ( TNF-α) and interleukin-1beta ( IL-1β) in the supernatant were determined by en-zyme-linked immunosorbent assay, and the expression of microtubule-associated protein 1 light chain 3 Ⅰ( LC3 Ⅰ) , LC3Ⅱ, P62 and Bcelin-1 was detected by Western blot. LC3Ⅱ∕LC3Ⅰ ratio was calculated. Results Compared with group Con, the cell viability was significantly decreased, the concentrations of TNF-α, IL-1β and NO and LC3Ⅱ∕LC3Ⅰratio were increased, and the expression of P62 and Beclin1 was up-regulated in group LPS (P<0. 05). Compared with group LPS, the cell viability was significantly in-creased, the concentrations of TNF-α, IL-1βand NO were decreased, LC3Ⅱ∕LC3Ⅰratio was increased, the expression of P62 was down-regulated, and the expression of Beclin1 was up-regulated in group LPS+DEX ( P<0. 05) . Compared with group LPS+Dex, the cell viability was significantly decreased, the con-centrations of TNF-α, IL-1β and NO were increased, LC3Ⅱ∕LC3Ⅰ ratio was decreased, the expression of P62 was up-regulated, and the expression of Beclin1 was down-regulated in group LPS+Dex+3-MA ( P<0. 05) . Conclusion Enhanced autophagy is involved in dexmedetomidine-induced reduction of LPS-caused inflammatory responses in macrophages of mice.