芥子酸对Aβ_(42)诱导PC12细胞损伤的改善作用及机制

Improvement effects of sinapic acid on Aβ_(42)-induced injury of PC12 cells and the mechanism

目的研究芥子酸对β-淀粉样蛋白42(Aβ_(42))诱导PC12细胞损伤的改善作用及机制。方法将PC12细胞分为对照组、模型组、芥子酸组、激活磷脂酰肌醇-3-激酶(PI3K)抑制剂组、细胞外信号调节蛋白激酶(ERK)抑制剂组,各抑制剂组先分别加入LY294002和U0126(均为10μmol/L)培养1 h;然后除对照组外,其余4组分别加入2μmol/LAβ_(42)处理24 h以复制阿尔茨海默病细胞模型;除对照组及模型组外,其余3组再分别加入100μmol/L芥子酸,继续培养24 h。检测细胞存活率并观察其形态,检测细胞中Aβ_(42)含量、cAMP反应元件结合蛋白(CREB)mRNA表达水平以及环磷酸腺苷(cAMP)、蛋白激酶A(PKA)、CREB、磷酸化CREB(p-CREB)蛋白表达水平。结果经芥子酸作用后,PC12细胞存活率、细胞中CREB mRNA表达水平以及cAMP、PKA、p-CREB蛋白表达水平均显著升高(P<0.05),细胞中Aβ_(42)含量显著降低(P<0.05),细胞形态明显改善、突触增多;而经PI3K、ERK抑制剂干预后,PC12细胞存活率及上述mRNA和蛋白表达水平均被显著逆转(P<0.05或P<0.01),细胞形态不规则、碎片增多,且突触连接减少。结论芥子酸可升高Aβ_(42)诱导损伤的PC12细胞存活率,改善细胞形态,降低细胞中Aβ_(42)含量,其作用机制可能与促进细胞中CREB mRNA转录、激活cAMP/PKA/CREB信号通路有关。

OBJECTIVE To study the improvement effects of sinapic acid on Aβ_(42)-induced injury of PC12 cells and the mechanism.METHODS PC12 cells were divided into five groups:control group,model group,sinapic acid group,phosphoinositide 3-kinase(PI3K)inhibitor group and extracellular signal-regulated kinase(ERK)inhibitor group.Each inhibitor group was added with LY294002 and U0126(10μmol/L)for 1 h;except for control group,other four groups were treated with 2μmol/L Aβ_(42)for 24 h to replicate the Alzheimer’s disease cell model;except for control group and model group,other three groups were added with 100μmol/L sinapic acid respectively.After 24 hours of continuous culture,survival rate of PC12 cells was detected and the morphology of PC12 cells was observed.The content of Aβ_(42),mRNA expression of cAMP response element binding protein(CREB),protein expression of cyclic adenosine monophosphate(cAMP),protein kinase A(PKA),CREB signaling pathway and phosphorylated CREB(p-CREB)were detected.RESULTS After treated with sinapic acid,the survival rate of PC12 cells,mRNA expression of CREB and protein expressions of cAMP,PKA and p-CREB were increased significantly(P<0.05),while the content of Aβ_(42)was decreased significantly(P<0.05);cell morphology was significantly improved and synapses increased.After intervened with PI3K and ERK inhibitors,the survival rate of PC12 cells,above mRNA and protein expressions were reversed significantly(P<0.05 or P<0.01);cell morphology was irregular,the fragments increased,and the synaptic connections decreased.CONCLUSIONS Sinapic acid can improve the survival rate of PC12 cells injured by Aβ_(42),improve cell morphology and decrease the content of Aβ_(42),the mechanism of which may be associated with promoting the gene transcription of CREB,and activating cAMP/PKA/CREB signaling pathway.