巨噬细胞中脂多糖诱导微小RNA-155表达与地塞米松的抑制

摘要

BACKGROUND:It is unclear about dexamethasone effect on the regulation of microRNA-155 expression in macrophages. OBJCTIVE:To explore whether dexamethasone can regulate the expression of microRNA-155 in macrophages. 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. 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.%背景：目前地塞米松对巨噬细胞中微小RNA-155表达的调控作用尚不明确。　　目的：了解地塞米松是否调节巨噬细胞中微小RNA-155的表达。　　方法：①脂多糖刺激小鼠巨噬细胞：体外培养小鼠巨噬细胞株 Raw264.7细胞，予脂多糖刺激。分别在培养0，0.5，2，6 h收集细胞，检测miRNA-155的动态表达。②地塞米松对巨噬细胞的干预：实验分4组：对照组予磷酸盐缓冲液培养；脂多糖组予脂多糖刺激；地塞米松+脂多糖组予地塞米松和脂多糖共同作用；地塞米松组予地塞米松培养。6 h后收集培养上清用ELISA法检测培养液中肿瘤坏死因子α、白细胞介素6等炎症因子表达，用实时荧光定量PCR法检测巨噬细胞中微小RNA-155的表达。　　结果与结论：①脂多糖刺激Raw264.7巨噬细胞6 h后炎症因子肿瘤坏死因子α、白细胞介素6及微小RNA-155表达明显增加(P<0.05)。②用地塞米松+脂多糖干预后炎症因子及微小RNA-155的表达轻度升高(P<0.05)。③单独地塞米松处理组中炎症因子无明显变化(P>0.05)，但微小RNA-155却明显减低(P<0.05)。④结果说明地塞米松抑制脂多糖诱导的巨噬细胞中微小RNA-155的表达。