基于IGF-1R/Akt/PGC-1α通路探讨芍药苷对H2O2诱导PC12细胞氧化损伤的保护作用

Protective Effects of Paeoniflorin on H2O2-induced Damage in PC12 Cells Based on IGF-1R/Akt/PGC-1α Pathway

目的研究芍药苷(Paeoniflorin,PF)对过氧化氢(H2O2)诱导高分化大鼠肾上腺嗜铬瘤细胞(PC12细胞)氧化损伤模型的保护作用及其机制。方法采用无血清H2O2体外诱导PC12细胞氧化损伤,并以不同浓度PF(100、200、300μmol·L-1)进行干预。采用噻唑蓝(MTT)法检测细胞存活率;倒置生物显微镜观察细胞形态;Annexin-V/PI双染法检测细胞凋亡率;ELISA法检测细胞内超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量和总抗氧化能力(T-AOC);Western Blot法检测胰岛素样生长因子-1受体(IGF-1R)、丝氨酸/苏氨酸激酶(Akt)、磷酸化Akt(p-Akt)、过氧化物酶体增殖物激活受体γ辅助激活因子-1α(PGC-1α)蛋白的表达水平。结果选择8μmol·L-1 H2O2作为模型复制浓度。与正常组比较,H2O2模型组细胞形态异常;细胞存活率明显降低、凋亡率显著升高(P<0.01);MDA含量增高(P<0.01),SOD活力及T-AOC降低(P<0.01);IGF-1R、Akt、pAkt及PGC-1α蛋白表达水平均明显下调(P<0.01)。与模型组比较,PF不同浓度组均能改善细胞形态,显著提高细胞存活率和降低细胞凋亡率(P<0.05,P<0.01);显著提高SOD酶活力和T-AOC(P<0.05,P<0.01),降低MDA含量(P<0.01,200、300μmol·L-1 PF组);明显上调IGF-1R、Akt及PGC-1α蛋白表达水平(P<0.05,P<0.01),提高Akt蛋白的磷酸化(p-Akt)水平(P<0.05,P<0.01)。结论PF可能是通过提高IGF-1R的表达,激活Akt/PGC-1α信号转导通路,增强细胞抗氧化损伤能力,抑制细胞凋亡,从而发挥保护H2O2损伤的PC12细胞的作用。

Objective To study the protective effect and mechanism of paeoniflorin(PF)on oxidative damage of PC12 cells induced by hydrogen peroxide(H2O2).Methods Oxidative damage of PC12 cells was induced in vitro by serum-free H2O2,and PF intervention was performed at different concentrations(100,200,300μmol·L-1).Cell viability was detected by methyl thiazolyl tetrazolium(MTT)method;morphology of the cells was observed by inverted microscopy.The cell apoptosis rate was detected by Annexin-V/PI double staining.The intracellular superoxide dismutase(SOD)activity,malondialdehyde(MDA)content and total antioxidant capacity(T-AOC)were detected by ELISA.The expression of insulin-like growth factor-1 receptor(IGF-1 R),serine/threonine kinase(Akt),p-Akt,peroxisome proliferator-receptor gamma coactivator(PGC-1α)proteins were detected by Western Blot.Results The oxidative damage model was induced by 8μmol·L-1 H2O2.Compared with the normal group,cells in the model group had abnormal morphology with significantly decreased cell viability and increased apoptosis rate(P<0.01),increased MDA content(P<0.01),decreased SOD activity and T-AOC(P<0.01),and significantly decreased expression levels of IGF-1 R,p-Akt,Akt and PGC-1α(P<0.01).Compared with the model group,different concentrations of PF ameliorated cell morphology,significantly increased cell viability and decreased apoptosis rate(P<0.05,P<0.01);significantly increased SOD activity and T-AOC(P<0.05,P<0.01),reduced MDA content(P<0.01,PF 200,300μmol·L-1 groups).PF was able to up-regulate the expression levels of IGF-1 R,Akt and PGC-1αprotein(P<0.05,P<0.01),and increased the phosphorylation level of p-Akt protein(P<0.05,P<0.01).Conclusion PF may play a role in protecting H2O2-injured PC12 cells by increasing the expression of IGF-1 R,activating the Akt/PGC-1αsignal transduction pathway,enhancing cellular antioxidant damage,and inhibiting apoptosis.