旋覆花内酯抑制血管平滑肌细胞炎性应答与阻断NF-κB活化有关  

1-o-acetylbritannilactone Inhibits Inflammatory Response by Suppressing NF-κB Activation

作　　者：刘月平[1] 韩梅[1] 温进坤[1] 郑斌[1] 

机构地区：[1]河北医科大学基础医学研究所,河北省医学生物技术重点实验室,石家庄050017

出　　处：《细胞生物学杂志》2007年第2期267-271,共5页Chinese Journal of Cell Biology

基　　金：国家自然科学基金(No.30472167);河北省自然科学基金(No.C2005000722)资助项目~~

摘　　要：应用免疫细胞化学染色及Western印迹检测血管平滑肌细胞(vascular smooth muscle cells,VSMC)环加氧酶-2(cyclo-oxygenase-2,COX-2)表达、NF-κB抑制蛋白α(IκB-α)水平和NF-κBp65核转位的变化;电泳迁移率改变分析(electrophoretic mobility shift assay,EMSA)确定旋覆花内酯(1-o-acetylbritannilactone,ABL)对核内NF-κBp65与DNA调控元件的结合活性的影响。结果表明,脂多糖(lipopolysaccharide,LPS)处理的VSMC,p65核转位加快,细胞核内的NF-κBp65水平快速升高,同时伴有IκB-α的减少;用ABL预处理VSMC后,LPS诱导的p65核转位增加及IκB-α减少受到明显抑制,抑制作用呈剂量依赖性。EMSA结果显示,LPS处理VSMC,其核蛋白与含有NF-κB结合位点的探针的结合活性升高;而用ABL预处理的VSMC,LPS诱导的核蛋白与探针结合活性的升高受到明显抑制。进而,ABL对NF-κB活化启动的下游炎性基因COX-2表达也具有较强的抑制效果。因此,ABL是一种抗炎物质,通过抑制NF-κB活化和炎性基因COX-2的表达而减弱或消除LPS诱导的VSMC炎症应答反应。Immunocytochemistry and Western blot analysis were adopted to measure the nuclear translocation of NF-kB p65 and the expression of IkB-α, cyclo-oxygenase-2 （COX-2）. Electrophoretic mobility shift assay （EMSA） was performed to detect DNA-binding activity of NF-kB in vascular smooth muscle cells （VSMC） pretreated with ABL. Western blot and immunocytochemistry analysis showed that lipopolysaccharide （LPS） treatment resulted in increasing nuclear translocation of NF-kB p65, and declining levels of IkB-α in VSMC. However, 1-o- acetylbritannilactone （ABL） pretreatment inhibited the nuclear translocation of p65 and degradation of IkB-α induced by LPS, and the inhibitory effect of ABL was concentration-dependent. LPS increased the binding of nuclear extracts from VSMC induced by LPS to double strands oligonucleotide probe containing NF-kB binding site using EMSA. The shift bands were abolished when a 100-fold excess of unlabeled NF-kB oligonucleotide probe was included. Pretreatment with ABL significantly reduced the nuclear level of NF-kB and declined the binding activity of nuclear extracts with DNA probe induced by LPS. Furthermore, ABL consequentially inhibited the expression of NF-kB-dependent COX-2 gene induced by LPS. These results suggest that ABL may be one anti-inflammatory drug which inhibits the expression of COX-2 gene by blocking NF-kB activation and thus suppresses the inflammatory response to LPS in VSMC

关 键 词：旋覆花内酯 血管平滑肌细胞 NF—kB 炎症反应 

分 类 号：R285.5[医药卫生—中药学]