二氢杨梅素抑制脂多糖诱导后BV2细胞HMGB1的核质转位和释放

目的 探索二氢杨梅素(Ampelopsin,AMP)对脂多糖(LPS)刺激的小胶质细胞BV2高迁移率族蛋白B1(HMGB1)核质转位和释放的影响。方法 不同浓度的二氢杨梅素(10μmol/L,30μmol/L,50μmol/L)联合LPS处理BV2细胞,用Elisa法检测HMGB1的分泌水平;细胞核质分离方法检测HMGB1核/质转位;免疫共沉淀检测HMGB1磷酸化的表达情况;免疫印迹检测JAK2、STAT3磷酸化水平。结果 不同浓度的二氢杨梅素显著抑制了LPS引起的BV2细胞HMGB1释放,减少了LPS诱导的HMGB1由细胞核到细胞质的转位。免疫共沉淀和免疫印迹结果表明:二氢杨梅素可减少HMGB1磷酸化水平,抑制LPS诱导的JAK2-STAT3信号通路激活。结论 二氢杨梅素可以抑制LPS介导的BV2细胞HMGB1的转位和释放,其主要机制可能是通过降低HMGB1的磷酸化以及抑制JAK2-STAT3信号途径。

Inhibitory effects of ampelopsin on translocation and secretion of HMGB1 in BV2 microglial cells induced by LPS

Objce tive To investigate the effects of ampelopsin ( AMP) on the nuclear/cytosolic translocation and secretion of high mobility group box 1 ( HMGB1) in BV2 cells induced by lipopolysaccharide ( LPS) .Methods Different concentrations of ampelopsin (10 μmol/L,30 μmol/L,50 μmol/L) were added to LPS-treated BV2 cells.The secretion level of HMGB1 was examined by specific Elisa assays .We further investigated whether ampelopsin could block HMGB 1 translocation from nuclear to cytoplasm during LPS treatments .The effect of ampelopsin on HMGB 1 phosphorylation was de-tected by co-immunoprecipitation .The expression of phosphorylated JAK 2 and STAT3 were detected by Western blotting . Results Ampelopsin at the dose of 50 μmol/L markedly attenuated HMGB 1 secretion after LPS treatment .The levels of nuclear HMGB1 were decreased and HMGB1 was accumulated in the cytoplasm after LPS .However,ampelopsin treatment obviously inhibited nucleus to cytoplasm translocation of HMGB 1.Co-immunoprecipitation results showed that ampelopsin pretreatment blocked HMGB 1 phosphorylation .Western blotting revealed that ampelopsin significantly down-regulated the phosphorylation of JAK2-STAT3 pathway in LPS-stimulated BV2 cells.Conclusion Pretreatment with ampelopsin before LPS suppressed HMGB1 secretion from activated microglia and its nuclear/cytosolic translocation through interfering with both JAK2/STAT3 signaling pathways and HMGB 1 phosphorylation .