双氢青蒿素抑制LPS诱导的小胶质细胞炎症反应

目的 观察双氢青蒿素(dih ydroartemisinin,DHA)对脂多糖(lipopolysaccharide,LPS)诱导的BV-2小胶质细胞神经炎症反应的影响及其机制.方法 LPS诱导BV-2小胶质细胞活化建立炎症模型,用不同浓度DHA(0.5、1、2、4μmol/L)处理细胞,CCK-8检测细胞活性;选取lμmol/L DHA干预细胞,倒置相差显微镜下观察细胞形态的变化;RT-PCR检测iNOS、IL-1β、IL-6、TNF-α基因表达水平;ELISA检测培养基中IL-1β、IL-6、TNF-α的表达水平;Western blot检测NF-κB、IκBα及TLR4的蛋白表达.结果 低剂量的DHA(＜2μmol/L)对BV-2细胞活性无明显影响(P＞0.05),DHA可抑制LPS引起的BV-2细胞形态变化,DHA抑制活化的BV-2细胞iNOS、IL-1β、IL-6、TNF-α mRNA的表达(P＜0.01),减少IL-1β、IL-6、TNF-α炎症因子释放(P＜0.01),明显降低TLR4的蛋白表达,减少细胞质内IκBα的表达,并抑制NF-κB向核内移位(P＜0.01).结论 DHA可能通过作用于TLR4/NF-κB通路,抑制LPS诱导的BV-2小胶质细胞NF-κB的激活,从而抑制炎症因子的产生,发挥抗炎作用.

Inhibitory effects of dihydroartemisinin on LPS-induced inflammatory response in BV-2 microglial cells

Objective To investigate the inhibitory effect of dihydroartemisinin (DHA) on lipopolysaccharide (LPS)-induced inflamnatory response in BV-2 nicroglial cells.Methods Inflammatory model was established by exposure of BV-2 cells to LPS for 24 h.Then after the cells were treated with different concentrations of DHA (0.5,1,2 and 4 μmol/L),cell viability was tested with CCK-8 assay.The cell morphology was observed under inverted phase contrast microscope after the inflammatory cell model under the treatment of a harmless concentration (1 μmol/L) of DHA,The mRNA expression of iNOS,IL-1 β,IL-6 and TNF-α was measured by RT-PCR.The contents of TNF-α,IL-1 β and IL-6 in the supernatant were detected by ELISA.The expression of the nuclear NF-κB (p65),IκBα,and TLR4 were analyzed by Western blotting.Results DHA showed no significant effect on cell viability when the concentration was lower than 2 μmol/L (P ＞ 0.05).DHA inhibited the cell morphological changes induced by LPS.DHA treatment resulted in the decreases in the mRNA expression levels of iNOS,IL-1 β,IL-6 and TNF-α (P ＜ 0.01),the production of pro-inflammatory cytokines IL-1β,IL-6,TNF-α,the protein levels of TLR4,intracytoplasmic IκBα and the nuclear translocation of NF-κB p65 (P ＜ 0.01).Conclusion DHA inhibits the inflammatory responses,activation of NF-κB of BV-2 microglial cells induced by LPS,and thus suppresses the production of pro-inflammatory cytokines,via TLR4/NF-κB signaling pathway.