摘要
目的探讨淫羊藿苷体外抑制猴免疫缺陷病毒(Simi-an immunodeficiency virus,SIV)复制作用和抑制SIV感染诱导的CEMx174细胞凋亡的信号转导机制。方法细胞病变和间接免疫荧光法测定了淫羊藿苷对SIV复制的抑制作用,Annexin V和Propidiumiodide(PI)双染法测定淫羊藿苷对SIV感染导致CEMx174细胞凋亡的作用,放免法测定了SIV感染CEMx174细胞内cAMP含量和依赖cAMP的蛋白激酶活性。Western blot法测定了PKA依赖的组蛋白磷酸化的水平。结果用不同浓度的淫羊藿苷处理细胞后结果表明,其半数毒性浓度为134mg·L-1,半数抑制浓度是26mg·L-1,治疗指数为5.15。淫羊藿苷对感染细胞凋亡的抑制要比正常细胞为高(P<0.05)。50mg·L-1淫羊藿苷作用病毒感染细胞15min后降低正常和感染细胞内的cAMP含量,但对感染细胞的cAMP含量影响更加明显。50mg·L-1淫羊藿苷可以显著下调感染和正常细胞的PKA活性(P<0.05)。病毒感染可以使磷酸化的组蛋白-H3升高,50 mg·L-1淫羊藿苷作用2h后,可以降低磷酸化组蛋白-H3的水平。结论淫羊藿苷体外对SIV复制有一定抑制作用,SIV-mac251感染导致的细胞凋亡是cAMP-PKA信号转导通路激活的结果,而短时间淫羊藿苷处理SIVmac251感染的CEMx174细胞可以暂时减缓SIVmac251诱导的细胞凋亡过程。
Aim To investigate the inhibitory effect of Icariin on replication of Simian immunodeficiency virus （SIV） and the signal transduction mechanism of Icariin inhibiting the apoptosis of CEM x174 triggered by SIV infection in vitro. Methods The inhibitory effect of Icariin on replication of SIV was evaluated by cyto- pathic effect and indirect immunofluorescene method. The apoptosis anlysis was performed by Annexin V and Propidiumiodide （PI） double dying, cAMP and the activity of cAMP-dependent protein kinase （PKA） were determined by radioimmunoaasay. Results Toxicity concentration（TC50） of Icariin on CEMx174 cell was 134 mg·L^-1 Inhibitory concentration（ICs0） was 26 mg·L^-1. Therapeutic index（TI） was 5.15. Icariin increased the percentage of viable cells while decreasing the percentage of apoptotic cells in both the normal and SIVmac251 infected group as well. ANOVA analysis showed that the effect of Icariin in the SIVmac251 infected group was more marked than in normal cells （ P 〈 0. 05 ）. The influence of Icariin on intracellular cAMP concentration 15 min post-infection was determined by RIA. Icariin at 50 mg·L^-1 reduced the concentration of cAMP in both normal and infected groups, but the effect was more marked in the latter （ ANOVA analysis P 〈 0. 01 ）. Icariin at 50 mg·L^-1 downregulated PKA activity in both normal and infected groups, but again was more marked in the latter （ ANOVA analysis P 〈 0. 05 ）. Conclusions These results suggested that apoptosis triggered by SIV- mac251 infection was a consequence of the cAMP-PKA signal transduction cascade. Short-term exposure of SIVmac251 infected CEMx174 cells to Icariin might temporarily alleviate the progression of apoptosis induced by SIVmac251.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2008年第5期684-687,共4页
Chinese Pharmacological Bulletin
基金
广东省自然科学基金资助项目(No06024151)
