姜酮通过激活Nrf2/HO-1信号通路减轻OGD/R后氧化应激损伤对HT22细胞凋亡的抑制作用

Inhibitory effect of gingerone on apoptosis of HT22 cells by alleviation oxidative stress damage after OGD/R through activating Nrf2/HO-1 signaling pathway

目的:探讨姜酮对氧糖剥夺/复糖复氧(OGD/R)后小鼠海马神经元HT22细胞的保护作用,阐明其相关作用机制。方法:培养HT22细胞,设置不同OGD/R时间梯度,建立OGD/R细胞损伤模型。HT22细胞分为对照组、OGD/R组、OGD/R+1μmol·L^(-1)姜酮组、OGD/R+10μmol·L^(-1)姜酮、OGD/R+100μmol·L^(-1)姜酮组和OGD/R+0.2%二甲亚枫(DMSO)组,CCK-8法检测各组细胞活性并计算各组细胞存活率,确定姜酮最适药物浓度。细胞分为对照组、OGD/R组、OGD/R+姜酮组和OGD/R+姜酮+核因子E2相关因子2(Nrf2)抑制剂(ML385)组,OGD/R+姜酮组细胞经姜酮给药处理4 h后予以OGD 8 h和复糖复氧8 h处理,OGD/R+姜酮+ML385组细胞在姜酮给药前予以10μmol·L^(-1)ML385预处理6 h,CCK-8法检测各组细胞活性,Western blotting法检测各组细胞中Nrf2、血红素加氧酶1(HO-1)、B细胞淋巴瘤2(Bcl-2)和Bcl-2相关X蛋白(Bax)蛋白表达水平,酶联免疫吸附试验(ELISA)法检测各组细胞培养上清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平。结果:与对照组比较,HT22细胞经OGD 8 h和复糖复糖8 h处理后细胞存活率低于50%,以OGD 8 h和复糖复糖8 h建立HT22细胞OGD/R模型。与OGD/R组比较,OGD/R+不同剂量姜酮组细胞存活率均不同程度升高,其中OGD/R+100μmol·L^(-1)姜酮组细胞存活率升高最明显(P<0.01),故选用100μmol·L^(-1)姜酮用于后续实验。与对照组比较,OGD/R组细胞活性明显降低(P<0.01),细胞中Nrf2、HO-1和Bax蛋白表达水平明显升高(P<0.01),Bcl-2蛋白表达水平明显降低(P<0.05),细胞培养上清中SOD活性明显降低(P<0.01),MDA水平明显升高(P<0.01);与OGD/R组比较,OGD/R+姜酮组细胞活性明显升高(P<0.01),细胞中Nrf2、HO-1和Bcl-2蛋白表达水平明显升高(P<0.05或P<0.01),Bax蛋白表达水平明显降低(P<0.05),细胞培养上清中SOD活性明显升高(P<0.01),MDA水平明显降低(P<0.01);与OGD/R+姜酮组比较,OGD/R+姜酮+ML385组细胞活性明显降低(P<0.01),细胞中Nrf2、HO-1和Bcl-2蛋白表达水平明显降低(P<0.01),Bax蛋白表达水平明显升高(P<0.01),细胞培养上清中SOD活性明显降低(P<0.01),MDA水平明显升高(P<0.05)。结论:姜酮可通过激活Nrf2/HO-1信号通路减轻OGD/R后氧化应激损伤对HT22细胞凋亡的抑制作用。

Objective:To discuss the protective effect of gingerone on the hippocampal neuron HT22 cells after oxygen-glucose deprivation/reoxygenation(OGD/R),and to clarify the related mechanism.Methods:The HT22 cells were cultured,and the OGD/R cell injury model was established by setting the gradient of OGD/R time.The HT22 cells were divided into control group,OGD/R group,OGD/R+1μmol·L^(-1) gingerone group,OGD/R+10μmol·L^(-1) gingerone group,OGD/R+100μmol·L^(-1) gingerone group,and OGD/R+0.2%dimethyl sulfoxide(DMSO)group.The viability of the cells in various groups was detected by CCK-8 assay;the survival rates of the cells in various groups were calculated to determine the optimal drug concentration of gingerone.The cells were divided into control,OGD/R group,OGD/R+gingerone,and OGD/R+gingerone+nuclear factor erythroid-2-related factor 2(Nrf2)inhibitor(ML385)groups.The cells in OGD/R+gingerone group were treated with gingerone for 4 h before OGD treatment for 8 h followed by reoxygenation for 8 h,and the cells in OGD/R+gingerone+ML385 group were treated with 10μmol·L^(-1) ML385 for 6 h before gingerone treatment.The viability of the cells in various groups was detected by CCK-8 assay;the expression levels of Nrf2,heme oxygenase-1(HO-1),B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)proteins in the cells in various groups were detected by Western blotting method;the activity of superoxide dismutase(SOD)and the level of malondialdehyde(MDA)in the cell culture supernatant in various groups were detected by enzyme-linked immunosorbent assay(ELISA)method.Results:Compared with control group,the survival rate of the HT22 cells was below 50%after treated with OGD for 8 h and reoxygenation for 8 h,so the HT22 cell OGD/R model was established by treated with OGD for 8 h and reoxygenation for 8 h.Compared with OGD/R group,the survival rates of the cells in OGD/R+different doses of gingerone groups were increased to various extents,and the survival rate of the cells in OGD/R+100μmol·L^(-1) gingerone group was significantly increased(P<0.01);so 100μmol·L^(-1) gingerone was used for the subsequent experiment.Compared with control group,the viability of the cells in OGD/R group was significantly decreased(P<0.01),and the expression levels of Nrf2,HO-1,and Bax proteins in the cells were significantly increased(P<0.01),while the expression level of Bcl-2 protein in the cells was significantly decreased(P<0.05),and the SOD activity in the cell culture supernatant was significantly decreased(P<0.01),and the level of MDA was significantly increased(P<0.01);compared with OGD/R group,the viability of the cells in OGD/R+gingerone group was significantly increased(P<0.01),and the expression levels of Nrf2,HO-1,and Bcl-2 proteins in the cells were significantly increased(P<0.05 or P<0.01),while the expression level of Bax protein in the cells was decreased(P<0.05),the SOD activity in the cell culture supernatant was significantly increased(P<0.01),and the level of MDA was significantly decreased(P<0.01);compared with OGD/R+gingerone group,the viability of the cells in OGD/R+gingerone+ML385 group was significantly decreased(P<0.01),and the expression levels of Nrf2,HO-1,and Bcl-2 proteins were significantly decreased(P<0.01),while the expression level of Bax protein in the cells was significantly increased(P<0.01),the SOD activity in the cell culture supernatant was significantly decreased(P<0.01),and the level of MDA was significantly increased(P<0.05).Conclusion:Gingerone alleviates the oxidative stress damage,and thereby plays an inhibiory effect on the apoptosis of the HT22 neurons by activating the Nrf2/HO-1 signaling pathway after OGD/R.