Dexamethasone inhibits the expression of microRNA-155 in macrophages induced by lipopolysaccharide

Wang Zhong-hua; Wang Shou-hong; Wu Yan; Li Zhou; Liao Xiao-long; Qin Tie-he

doi:10.3969/j.issn.2095-4344.2016.11.011

Abstract：BACKGROUND:It is unclear about dexamethasone effect on the regulation of microRNA-155 expression in macrophages. <br> OBJCTIVE:To explore whether dexamethasone can regulate the expression of microRNA-155 in macrophages. <br> METHODS:(1) Lipopolysaccharide stimulation of mouse macrophages: mouse macrophage cel lines, Raw264.7 cels, were culturedin vitro and stimulated by lipopolysaccharide. Cultured cels were colected at 0, 0.5, 2, 6 hours after culture to detect the dynamical expression of microRNA-155. (2) Dexamethasone intervention for macrophages: Macrophages were divided into four groups: control group treated with phosphate buffer; lipopolysaccharide group stimulated by lipopolysaccharide; combined group given intervention with dexamethasone and lipopolysaccharide; dexamethasone group cultured with dexamethasone. At 6 hours after culture, cel supernatant was colected to detect the expression of tumor necrosis factor α and interleukin-6 using ELISA method. Real-time fluorescence quantitative PCR was used to detect the expression of microRNA-155 in the Raw264.7 macrophages. <br> RESULTS AND CONCLUSION:Lipopolysaccharide significantly increased the expression of tumor necrosis factor α, interleukin-6 and microRNA-155 after 6 hours of culture (P < 0.05). Combined use of dexamethasone and lipopolysaccharide slightly increased the expression of tumor necrosis factor α, interleukin-6 and microRNA-155 (P< 0.05). Dexamethasone alone had no influence on the expression of tumor necrosis factor α and interleukin-6, but significantly decreased the expression of microRNA-155 (P < 0.05). These findings indicate that dexamethasone can inhibit the expression of microRNA-155 in the macrophages induced by lipopolysaccharide.