三七皂苷 R1对过氧化氢诱导大鼠星形胶质细胞凋亡的影响

摘要

Objective To investigate the effect of notoginsenoside R1(NTR1) preventing astrocytes from H2O2 induced apoptosis, and the related mechanism. Methods Primary cultured astrocytes were exposed to 200μmol/L H2O2 for 24 h for inducing apoptosis, and the NTR1 was added into the culture medium before the H2O2 of 24 h. The rate of apoptosis was assayed by Annexin V-FITC/PI staining and flow cytometry analysis, and the Caspase-3 activity were detected by color metric assay. The BAD and BCL2 mRNA expression levels measured by Real time quantitive polymerase chain reaction (qRT-PCR), and the BAD, BCL2, STAT and p-STAT(Y705) protein level detected by Western blot. Results The apoptosis rate and Caspase-3 activity had increased on astrocytes induced by H2O2, but NTR1 can prevent such effects especially in 50 μmol/L and 100μmol/L. The H2O2 could induce the expression of BAX and suppress the expression of BCL2 on mRNA level and protein level. Relative to control group, cells within NTR1 could express less BAX and more BCL2 on mRNA level and protein level, but NTR1 could not affect the intracellular levels of STAT3 or p-STAT3 (Y705). Conclusion NTR1 could prevent astrocytes from H2O2 induced apoptosis and restore the balance between BAX and BCL2, but those effects might be not related to STAT3 signal pathways.%目的：探讨三七皂苷R1保护大鼠皮质星形胶质细胞免于过氧化氢诱导的凋亡作用及相关分子机制。方法利用200μmol/L过氧化氢处理胶质细胞24 h建立凋亡模型，加入10μmol/L、50μmol/L及100μmol/L 三七皂苷 R1预处理胶质细胞24 h 后与200μmol/L 过氧化氢共同作用24 h，通过 Annexin V-FITC/PI双染法流式细胞分析仪检测各组凋亡率和检测Caspase-3的活性水平。利用实时定量RT-PCR与Western blot检测BAX与BCL2的mRNA水平和蛋白表达量，并检测各组的STAT3蛋白表达量及其Y705位点的磷酸化水平。结果过氧化氢诱导凋亡24 h后，对照组胶质细胞凋亡率及Caspase-3活性上升，加三七皂苷 R1处理后凋亡率及 Caspase-3活性下降，其中50μmol/L 浓度组与100μmol/L 浓度组的凋亡率与Caspase-3活性与对照组差异显著（P<0.05）。相对于对照组，加入三七皂苷R1处理后BAX基因的mRNA及蛋白表达水平降低，BCL2基因的mRNA及蛋白表达水平上升。STAT3蛋白表达量在经过氧化氢处理后蛋白表达无变化，其Y705位点的磷酸化水平明显上升，加入三七皂苷R1处理后STAT3蛋白表达量及磷酸化水平无显著变化。结论三七皂苷R1能通过恢复凋亡相关基因BAX与BCL2的平衡，保护大鼠皮质星形胶质细胞免于过氧化氢诱导的凋亡作用，但其相关机制可能与STAT3信号通路无关。